diff --git a/setup.cfg b/setup.cfg
index dd2961d13934c88b13535a0cc1c17b6d7dbd74e3..205fc60074589ac11c745ade435525602af6b434 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,8 +19,8 @@ package_dir =
 packages = find:
 python_requires = >=3.7
 install_requires =
-	importlib-resources
-	caosadvancedtools >= 0.7.0
+    importlib-resources
+    caosadvancedtools >= 0.7.0
     linkahead > 0.13.2
     yaml-header-tools >= 0.2.1
     pyyaml
diff --git a/src/caoscrawler/crawl.py b/src/caoscrawler/crawl.py
index 4990aecc025c290bed26e05d73833b756f904b46..e0bddb57a987e38b0e4b782d399bc94cb4a84eae 100644
--- a/src/caoscrawler/crawl.py
+++ b/src/caoscrawler/crawl.py
@@ -761,8 +761,8 @@ class Crawler(object):
                 # 1. Is it in the cache of already checked Records?
                 if self.treated_records_lookup.get_any(record, identifiable) is not None:
                     treated_record = self.treated_records_lookup.get_any(record, identifiable)
-                    # Since the identifiables are the same, treated_record and record actually describe
-                    # the same obejct.
+                    # Since the identifiables are the same, treated_record and record actually
+                    # describe the same object.
                     # We merge record into treated_record in order to prevent loss of information
                     self._merge_identified(treated_record, record, try_to_merge_later, all_records)
                     referencing_entities = self.create_reference_mapping(all_records)
diff --git a/src/caoscrawler/identifiable_adapters.py b/src/caoscrawler/identifiable_adapters.py
index d94b6fca211fc26c2702b8f9f5ad4bc8993bd920..d661b97a6ef158bf05b66ac79cf0520921abef0a 100644
--- a/src/caoscrawler/identifiable_adapters.py
+++ b/src/caoscrawler/identifiable_adapters.py
@@ -221,23 +221,24 @@ startswith: bool, optional
         for prop in registered_identifiable.properties:
             if prop.name.lower() != "is_referenced_by":
                 continue
-            for givenrt in prop.value:
+            for looking_for_rt in prop.value:
                 found = False
-                if givenrt == "*":
+                if looking_for_rt == "*":
                     for val in referencing_entities.values():
                         if len(val) > 0:
                             found = True
                         refs.extend(val)
                 else:
-                    rt_and_children = get_children_of_rt(givenrt)
+                    rt_and_children = get_children_of_rt(looking_for_rt)
                     for rtname in rt_and_children:
                         if (rtname in referencing_entities):
                             refs.extend(referencing_entities[rtname])
                             found = True
             if not found:
                 raise NotImplementedError(
-                    f"An identifying property:\n"
-                    f"\nIdentifying PROPERTY\n{prop.name}"
+                    f"Could not find referencing entities of type(s): {prop.value}\n"
+                    f"for registered identifiable:\n{registered_identifiable}\n"
+                    f"There were {len(referencing_entities)} referencing entities to choose from."
                 )
         return refs
 
@@ -260,8 +261,8 @@ startswith: bool, optional
 
     def get_identifiable(self, record: db.Record, referencing_entities=None):
         """
-        retrieve the registered identifiable and fill the property values to create an
-        identifiable
+        Retrieve the registered identifiable and fill the property values to create an
+        identifiable.
 
         Args:
             record: the record for which the Identifiable shall be created.
diff --git a/src/doc/README_SETUP.md b/src/doc/README_SETUP.md
index 5f5161d0d672ff3ad14db5c5b49f5c65550b06d7..a75193783d861707adf3b3d45311c392e22626f4 100644
--- a/src/doc/README_SETUP.md
+++ b/src/doc/README_SETUP.md
@@ -4,7 +4,10 @@
 see INSTALL.md
 
 ## Run Unit Tests
-Run `pytest unittests`.
+
+1. Install additional dependencies:
+  - h5py
+2. Run `pytest unittests`.
 
 ## Documentation ##
 We use sphinx to create the documentation. Docstrings in the code should comply