diff --git a/README.md b/README.md
index 1106e9da..a3a1c6e5 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,6 @@ To be able to build and run the Java Spring Boot application, you need the follo
   (see instructions below to install and run in Docker)
 - Java JDK at least recent enough to run Gradle
   (JDK 17.x will be automatically installed by Gradle toolchain support)
-- Gradle in some not too outdated version (7.4 will be installed via wrapper)
 
 You also might need an IDE (e.g. *IntelliJ IDEA* or *Eclipse* or *VS Code* with *[STS](https://spring.io/tools)* and a GUI Frontend for *PostgreSQL* like *Postbird*.
 
@@ -62,12 +61,16 @@ If you have at least Docker, the Java JDK and Gradle installed in appropriate ve
 
     cd your-hsadmin-ng-directory
     
-    gradle wrapper  # downloads the configured Gradle version into the project
-    source .aliases # creates some comforable bash aliases, e.g. 'gw'='./gradlew'
+    source .aliases # creates some comfortable bash aliases, e.g. 'gw'='./gradlew'
+    gw              # initially downloads the configured Gradle version into the project
 
     gw test         # compiles and runs unit- and integration-tests
     
+    # if the container has not been built yet, run this:
     pg-sql-run      # downloads + runs PostgreSQL in a Docker container on localhost:5432
+    # if the container has been built already, run this:
+    pg-sql-start
+
     gw bootRun      # compiles and runs the application on localhost:8080
 
     # the following command should reply with "pong":
@@ -418,6 +421,21 @@ Underneath of rbac and hs, the structure is business oriented, NOT technical / l
 Some of these rules are checked with *ArchUnit* unit tests.
 
 
+### Run Tests from Command Line
+
+Run all tests which have not yet been passed with the current source code:
+
+```shell
+gw test 
+```
+
+Force running all tests:
+
+```shell
+gw cleanTest test 
+```
+
+
 ### Spotless Code Formatting
 
 Code formatting for Java is checked via *spotless*.
@@ -576,7 +594,7 @@ Summary for Debian-based Linux systems:
 sudo apt-get -y install podman
 ```
 
-2Then start it like this:
+Then start it like this:
 
 ```shell
 systemctl --user enable --now podman.socket
@@ -607,7 +625,7 @@ we need to register a shutdown-hook in the test source code.
 2. Now You Can Run the Tests
 
 ```shell
-gw clean test # gw is from the .aliases file
+gw test # gw is from the .aliases file
 ```
 
 #### Use IntelliJ IDEA Run the Tests Against the Podman Daemon
diff --git a/build.gradle b/build.gradle
index 29ad0e23..1be9d95f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -67,6 +67,7 @@ dependencies {
     implementation 'org.apache.commons:commons-text:1.10.0'
     implementation 'org.modelmapper:modelmapper:3.1.0'
     implementation 'org.iban4j:iban4j:3.2.3-RELEASE'
+    implementation 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.2.0'
 
     compileOnly 'org.projectlombok:lombok'
     testCompileOnly 'org.projectlombok:lombok'
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/relationship/HsOfficeRelationshipController.java b/src/main/java/net/hostsharing/hsadminng/hs/office/relationship/HsOfficeRelationshipController.java
index 3d6332e3..98c6bccf 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/relationship/HsOfficeRelationshipController.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/relationship/HsOfficeRelationshipController.java
@@ -51,7 +51,7 @@ public class HsOfficeRelationshipController implements HsOfficeRelationshipsApi
             final HsOfficeRelationshipTypeResource relationshipType) {
         context.define(currentUser, assumedRoles);
 
-        final var entities = relationshipRepo.findRelationshipRelatedToPersonUuid(personUuid,
+        final var entities = relationshipRepo.findRelationshipRelatedToPersonUuidAndRelationshipType(personUuid,
                 mapper.map(relationshipType, HsOfficeRelationshipType.class));
 
         final var resources = mapper.mapList(entities, HsOfficeRelationshipResource.class,
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/relationship/HsOfficeRelationshipRepository.java b/src/main/java/net/hostsharing/hsadminng/hs/office/relationship/HsOfficeRelationshipRepository.java
index 8b9e10fe..d34caa8c 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/relationship/HsOfficeRelationshipRepository.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/relationship/HsOfficeRelationshipRepository.java
@@ -12,8 +12,8 @@ public interface HsOfficeRelationshipRepository extends Repository<HsOfficeRelat
 
     Optional<HsOfficeRelationshipEntity> findByUuid(UUID id);
 
-    default List<HsOfficeRelationshipEntity> findRelationshipRelatedToPersonUuid(@NotNull UUID personUuid, HsOfficeRelationshipType relationshipType) {
-        return findRelationshipRelatedToPersonUuid(personUuid, relationshipType.toString());
+    default List<HsOfficeRelationshipEntity> findRelationshipRelatedToPersonUuidAndRelationshipType(@NotNull UUID personUuid, HsOfficeRelationshipType relationshipType) {
+        return findRelationshipRelatedToPersonUuidAndRelationshipTypeString(personUuid, relationshipType.toString());
     }
 
     @Query(value = """
@@ -27,7 +27,7 @@ public interface HsOfficeRelationshipRepository extends Repository<HsOfficeRelat
                 WHERE (:relationshipType IS NULL OR p.relType = cast(:relationshipType AS HsOfficeRelationshipType))
                     AND ( p.relAnchorUuid = :personUuid OR p.relHolderUuid = :personUuid)
                """, nativeQuery = true)
-    List<HsOfficeRelationshipEntity> findRelationshipRelatedToPersonUuid(@NotNull UUID personUuid, String relationshipType);
+    List<HsOfficeRelationshipEntity> findRelationshipRelatedToPersonUuidAndRelationshipTypeString(@NotNull UUID personUuid, String relationshipType);
 
     HsOfficeRelationshipEntity save(final HsOfficeRelationshipEntity entity);
 
diff --git a/src/test/resources/application.yml b/src/test/resources/application.yml
index 9915854e..a4f570f9 100644
--- a/src/test/resources/application.yml
+++ b/src/test/resources/application.yml
@@ -4,7 +4,7 @@ spring:
             platform: postgres
 
     datasource:
-        url: jdbc:tc:postgresql:13.7-bullseye:///spring_boot_testcontainers
+        url: jdbc:tc:postgresql:15.5-bookworm:///spring_boot_testcontainers
         url-local: jdbc:postgresql://localhost:5432/postgres
         username: postgres
         password: password