diff --git a/oaipmh-core/pom.xml b/oaipmh-core/pom.xml
index b9d2db8e7299590577a0dae5ae6db98d25575b2b..a799db515abcb021d561c855a1c30e94ec5a1cf0 100644
--- a/oaipmh-core/pom.xml
+++ b/oaipmh-core/pom.xml
@@ -16,7 +16,7 @@
 		<dependency>
 			<groupId>org.eclipse.rdf4j</groupId>
 			<artifactId>rdf4j-repository-api</artifactId>
-			<version>3.0.2</version>
+			<version>${rdf4j-repository-api.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>info.textgrid.middleware</groupId>
@@ -74,40 +74,18 @@
 			<artifactId>elasticsearch-rest-high-level-client</artifactId>
 			<version>${elasticsearch.version}</version>
 		</dependency>
-		<!-- <dependency> -->
-		<!-- <groupId>org.slf4j</groupId> -->
-		<!-- <artifactId>slf4j-api</artifactId> -->
-		<!-- <version>${slf4j.version}</version> -->
-		<!-- </dependency> -->
-		<!-- <dependency> -->
-		<!-- <groupId>org.slf4j</groupId> -->
-		<!-- <artifactId>jcl-over-slf4j</artifactId> -->
-		<!-- <version>${slf4j.version}</version> -->
-		<!-- <scope>runtime</scope> -->
-		<!-- </dependency> -->
-		<!-- <dependency> -->
-		<!-- <groupId>org.slf4j</groupId> -->
-		<!-- <artifactId>slf4j-log4j12</artifactId> -->
-		<!-- <version>${slf4j.version}</version> -->
-		<!-- <scope>runtime</scope> -->
-		<!-- </dependency> -->
-		<!-- <dependency> -->
-		<!-- <groupId>log4j</groupId> -->
-		<!-- <artifactId>log4j</artifactId> -->
-		<!-- <version>1.2.14</version> -->
-		<!-- </dependency> -->
-
+<!--
 		<dependency>
 			<groupId>org.apache.logging.log4j</groupId>
 			<artifactId>log4j-api</artifactId>
-			<version>2.13.0</version>
+			<version>${log4j.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.logging.log4j</groupId>
 			<artifactId>log4j-core</artifactId>
-			<version>2.13.0</version>
+			<version>${log4j.version}</version>
 		</dependency>
-
+-->
 		<dependency>
 			<groupId>org.classicmayan.tools</groupId>
 			<artifactId>metsModsMapping</artifactId>
@@ -116,25 +94,24 @@
 		<dependency>
 			<groupId>de.shadowhunt.maven.plugins</groupId>
 			<artifactId>package-info-maven-plugin</artifactId>
-			<version>1.4.5</version>
+			<version>${package-info-maven-plugin.version}</version>
 		</dependency>
 		<!-- https://mvnrepository.com/artifact/org.json/json -->
 		<dependency>
 			<groupId>org.json</groupId>
 			<artifactId>json</artifactId>
-			<version>20190722</version>
+			<version>${json.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-web</artifactId>
 			<version>${spring.version}</version>
 		</dependency>
-
 		<!-- https://mvnrepository.com/artifact/com.thoughtworks.xstream/xstream -->
 		<dependency>
 			<groupId>com.thoughtworks.xstream</groupId>
 			<artifactId>xstream</artifactId>
-			<version>1.4.12</version>
+			<version>${xstream.version}</version>
 		</dependency>
 	</dependencies>
 	<build>
@@ -201,7 +178,7 @@
 			<plugin>
 				<groupId>org.jvnet.jaxb2.maven2</groupId>
 				<artifactId>maven-jaxb2-plugin</artifactId>
-				<version>0.14.0</version>
+				<version>${maven-jaxb2-plugin.version}</version>
 				<executions>
 					<execution>
 						<id>generate-oaipmh</id>
@@ -222,7 +199,7 @@
 					<dependency>
 						<groupId>org.jvnet.jaxb2_commons</groupId>
 						<artifactId>jaxb2-namespace-prefix</artifactId>
-						<version>1.3</version>
+						<version>${jaxb2-namespace-prefix.version}</version>
 					</dependency>
 				</dependencies>
 			</plugin>
diff --git a/pom.xml b/pom.xml
index 5fd9cab3aa678d08cd600e6378a7b59c0d9908cd..1447f8ad04ce7e04ee82907b286f8cd8cf5d25a4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -15,17 +15,22 @@
         <common.version>4.2.0-SNAPSHOT</common.version>
 		<cxf.version>3.3.12</cxf.version>
         <elasticsearch.version>6.5.4</elasticsearch.version>
-        <jaxb2-maven-plugin.version>2.5.0</jaxb2-maven-plugin.version>
-		<jetty-maven-plugin.version>9.4.12.v20180830</jetty-maven-plugin.version>
-        <junit.version>4.13.1</junit.version>
+        <jaxb2-namespace-prefix.version>1.3</jaxb2-namespace-prefix.version>
+        <jetty-maven-plugin.version>9.4.12.v20180830</jetty-maven-plugin.version>
+		<junit.version>4.13.1</junit.version>
+        <json.version>20190722</json.version>
         <maven-antrun-plugin.version>1.3</maven-antrun-plugin.version>
         <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
         <maven-deploy-plugin.version>2.8.2</maven-deploy-plugin.version>
         <maven-eclipse-plugin.version>2.10</maven-eclipse-plugin.version>
+        <maven-jaxb2-plugin.version>0.14.0</maven-jaxb2-plugin.version>
 		<mets-mods-mapping.version>1.1.25</mets-mods-mapping.version>
+        <package-info-maven-plugin.version>1.4.5</package-info-maven-plugin.version>
         <properties-maven-plugin.version>1.0-alpha-2</properties-maven-plugin.version>
-        <slf4j.version>1.7.5</slf4j.version>
+        <!-- <slf4j.version>1.7.5</slf4j.version> -->
+        <rdf4j-repository-api.version>3.0.2</rdf4j-repository-api.version>
 		<spring.version>4.0.2.RELEASE</spring.version>
+        <xstream.version>1.4.18</xstream.version>
 	</properties>
 	<url>https://gitlab.gwdg.de/dariah-de/dariah-de-oai-pmh-services</url>
 	<scm>