diff --git a/organize/interfaces.py b/organize/interfaces.py
index b0bd4b3..58ed910 100644
--- a/organize/interfaces.py
+++ b/organize/interfaces.py
@@ -493,7 +493,21 @@ class IWorkItems(Interface):
     """ A collection (manager, container) of work items.
     """
 
+    def __getitem__(key):
+        """ Return the work item identified by the key given.
+        """
+
+    def __iter__():
+        """ Return an iterator of all work items.
+        """
+
+    def query(**criteria):
+        """ Search for tracks. Possible criteria are: task, party, run,
+            timeFrom, timeTo.
+        """
+
     def add(task, party, run=0, **kw):
         """ Create and register a work item; return it. Additional properties
             may be specified via keyword arguments.
         """
+
diff --git a/organize/work.py b/organize/work.py
index e389c29..b10d2a7 100644
--- a/organize/work.py
+++ b/organize/work.py
@@ -228,6 +228,15 @@ class WorkItems(object):
     def __iter__(self):
         return iter(self.context.values())
 
+    def query(self, **criteria):
+        if 'task' in criteria:
+            criteria['taskId'] = criteria.pop('task')
+        if 'party' in criteria:
+            criteria['userName'] = criteria.pop('party')
+        if 'run' in criteria:
+            criteria['runId'] = criteria.pop('run')
+        return self.context.query(**criteria)
+
     def add(self, task, party, run=0, **kw):
         trackId = self.context.saveUserTrack(task, run, party, {})
         track = self[trackId]