diff --git a/src/main/java/w2phtml/rdf/DocumentStructure.java b/src/main/java/w2phtml/rdf/DocumentStructure.java
index 25f085a..c6decc5 100644
--- a/src/main/java/w2phtml/rdf/DocumentStructure.java
+++ b/src/main/java/w2phtml/rdf/DocumentStructure.java
@@ -18,6 +18,8 @@ import org.apache.jena.ontology.OntModel;
 import org.apache.jena.rdf.model.ModelFactory;
 import org.apache.jena.rdf.model.Resource;
 import org.apache.jena.vocabulary.*;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import w2phtml.xhtml.XhtmlConfig;
 import w2phtml.xhtml.XhtmlDocument;
@@ -26,6 +28,24 @@ import org.apache.jena.rdf.model.Property;
 
 
 public class DocumentStructure {
+	
+	private static final String AFFILIATED_ORGANIZATION_POSTAL_CODE = "affiliated organization postal code";
+
+	private static final String AFFILIATED_ORGANIZATION_ADDRESS = "affiliated organization address";
+
+	private static final String AFFILIATED_ORGANIZATION_OFFICIAL_NAME = "affiliated organization official name";
+
+	private static final String AFFILIATED_ORGANIZATION_NAME = "affiliated organization name";
+
+	private static final String AUTHOR_INITIALS = "author initials";
+
+	private static final String AUTHOR_EMAIL = "author email";
+
+	private static final String AUTHOR_FAMILY = "author family";
+
+	private static final Logger logger = LoggerFactory.getLogger(DocumentStructure.class);
+
+	private static final String AUTHOR_GIVEN_NAME = "author given name";
 	private static final String MODIFICATION_TIME = "modificationTime";
   private static final String HTML_EXCERPT_PROPERTY = "htmlExcerpt";
 	private static final String TOCITEM = "TOCItem";
@@ -211,80 +231,79 @@ public class DocumentStructure {
 	  mainResource.addProperty( property, todayAsString);
   }
 	
-	private void addAuthor(Resource resource, DocumentPart docPart) {
+	private void addAuthor(Resource excerpt, DocumentPart docPart) {
 		String order = docPart.getOrder();				
 		ArrayList<Map<String, String>> sectionMeta = metadata.getSection(order);
 		for (Map<String, String> map : sectionMeta) {
 			Set<String> names = map.keySet();
-			if (names.contains("author given name")) {
-				attachAuthor(resource, map, order);
+			for (String givenNameKey : names) {
+				if (givenNameKey.startsWith(AUTHOR_GIVEN_NAME)) {
+					String postfix = givenNameKey.replaceFirst(AUTHOR_GIVEN_NAME, "");
+					if (!postfix.matches("[a-zA-Z0-9]*")) {
+						logger.error("Metadata author postfix is bad. Should contain only symbols a-zA-Z0-9, but "
+						+ postfix + " found. Author givenName field is " + givenNameKey );
+						System.exit(1);
+					}
+					String participantURI = TS + PARTICIPANT + "/" + PARSERNAME + "_" + docID + order + "author" + postfix;
+					Resource participant = m.createResource(participantURI, participantClass);
+					Property hasAuthor = m.createProperty(TS + "hasAuthor");
+					excerpt.addProperty(hasAuthor, participant);
+					String givenName = map.get(givenNameKey);
+					Property givenNameProperty = m.createProperty(TS + "participantGivenName");
+					participant.addProperty( givenNameProperty, givenName.trim());
+					
+					String family = map.get(AUTHOR_FAMILY + postfix);
+					if (family != null) {
+						Property familyProperty = m.createProperty(TS + "participantFamily");
+						participant.addProperty( familyProperty, family.trim());
+					}
+					String labelName = givenNameKey.trim();
+					if (family != null ) {
+						labelName += " " + family;
+					}
+					participant.addProperty(RDFS.label, labelName);
+					
+					String email = map.get(AUTHOR_EMAIL + postfix);
+					if (email != null) {
+						Property emailProperty = m.createProperty(TS + "participantEmail");
+						participant.addProperty( emailProperty, email.trim());
+					}
+					String authorInitials = map.get(AUTHOR_INITIALS + postfix);
+					if (email != null) {
+						Property initialsProperty = m.createProperty(TS + "participantInitials");
+						participant.addProperty( initialsProperty, authorInitials.trim());
+					}
+					attachOrganization(participant, map, order, postfix);
+				}
 			}
 		}
 	}
 
-	private void attachAuthor(Resource resource, Map<String, String> map, String order) {
-		String participantURI = TS + PARTICIPANT + "/" + PARSERNAME + "_" + docID + order ;
-		Resource participant = m.createResource(participantURI, participantClass);
-		Property hasAuthor = m.createProperty(TS + "hasAuthor");
-		resource.addProperty(hasAuthor, participant);
-		createParticipant(map, order, participant);
-	}
-
-	private void createParticipant(Map<String, String> map, String order, Resource participant) {
-		String givenName = map.get("author given name");
-		if (givenName != null) {
-			Property givenNameProperty = m.createProperty(TS + "participantGivenName");
-			participant.addProperty( givenNameProperty, givenName.trim());
-		}
-		String family = map.get("author family");
-		if (family != null) {
-			Property familyProperty = m.createProperty(TS + "participantFamily");
-			participant.addProperty( familyProperty, family.trim());
-		}
-		if (givenName != null ) {
-			String labelName = givenName.trim();
-			if (family != null ) {
-				labelName += " " + family;
-			}
-			participant.addProperty(RDFS.label, labelName);
-		}
-		String email = map.get("author email");
-		if (email != null) {
-			Property emailProperty = m.createProperty(TS + "participantEmail");
-			participant.addProperty( emailProperty, email.trim());
-		}
-		String authorInitials = map.get("author initials");
-		if (email != null) {
-			Property initialsProperty = m.createProperty(TS + "participantInitials");
-			participant.addProperty( initialsProperty, authorInitials.trim());
-		}
-		attachOrganization(participant, map, order);
-	}
-
-	private void attachOrganization(Resource participant, Map<String, String> map, String order) {
-		String orgName = map.get("affiliated organization name");
-		System.out.println(orgName);
+	private void attachOrganization(Resource participant, Map<String, String> map, String order, String postfix) {
+		String orgName = map.get(AFFILIATED_ORGANIZATION_NAME + postfix);
 		if (orgName == null) {
+			System.out.println(orgName + " not found");
+			logger.warn("No " + AFFILIATED_ORGANIZATION_NAME + postfix + " found.");
 			return;
 		}
-		String organizationUri = TS + ORGANIZATION + "/" + PARSERNAME + "_" + docID + order;
+		String organizationUri = TS + ORGANIZATION + "/" + PARSERNAME + "_" + docID + order + "author" + postfix;
 		Resource organization = m.createResource(organizationUri, organizationClass);
 		Property affiliatedWith = m.createProperty(TS + "affiliatedWith");
 		participant.addProperty(affiliatedWith, organization);
 	
 		organization.addProperty(RDFS.label, orgName);
 
-		String officialName = map.get("affiliated organization official name");
+		String officialName = map.get(AFFILIATED_ORGANIZATION_OFFICIAL_NAME + postfix);
 		if (officialName != null) {
 			Property officialNameProperty = m.createProperty(TS + "officialOrganizationName");
 			organization.addProperty(officialNameProperty, officialName);
 		}
-		String orgAddress = map.get("affiliated organization address");
+		String orgAddress = map.get(AFFILIATED_ORGANIZATION_ADDRESS + postfix);
 		if (orgAddress != null) {
 			Property orgAddressProperty = m.createProperty(TS + "organizationAddress");
 			organization.addProperty(orgAddressProperty, orgAddress);
 		}
-		String postalCode = map.get("affiliated organization postal code");
+		String postalCode = map.get(AFFILIATED_ORGANIZATION_POSTAL_CODE + postfix);
 		if (postalCode != null) {
 			Property postalCodeProperty = m.createProperty(TS + "organizationPostalCode");
 			organization.addProperty(postalCodeProperty, postalCode);