diff --git a/tests/test_sources.py b/tests/test_sources.py
index 5e84c8c..f45789a 100644
--- a/tests/test_sources.py
+++ b/tests/test_sources.py
@@ -18,7 +18,7 @@ except ImportError:
 import examples
 
 # -- SUT
-from tldp.sources import SourceDirs, SourceDocument
+from tldp.sources import SourceCollection, SourceDocument
 
 datadir = os.path.join(os.path.dirname(__file__), 'testdata')
 
@@ -29,7 +29,7 @@ def stem_and_ext(name):
     return stem, ext
 
 
-class TestSourceDirs(unittest.TestCase):
+class TestSourceCollection(unittest.TestCase):
 
     def setUp(self):
         self.tempdir = mkdtemp(prefix='tldp-sources-test-')
@@ -59,7 +59,7 @@ class TestSourceDirs(unittest.TestCase):
         return relname, newname
 
 
-class TestFileSourceDirsMultiDir(TestSourceDirs):
+class TestFileSourceCollectionMultiDir(TestSourceCollection):
 
     def test_multidir_finding_singlefiles(self):
         ex = random.choice(examples.examples)
@@ -69,21 +69,21 @@ class TestFileSourceDirsMultiDir(TestSourceDirs):
         for d in documents:
             d.reldir, d.absdir = self.mkdir_components(d.components)
             d.relname, d.absname = self.addfile(d.absdir, ex, stem=d.stem)
-        s = SourceDirs([x.absdir for x in documents])
+        s = SourceCollection([x.absdir for x in documents])
         self.assertEquals(2, len(s))
         sought = set([x.stem for x in documents])
         found = set([x for x in s])
         self.assertEquals(sought, found)
 
 
-class TestFileSourceDirsOneDir(TestSourceDirs):
+class TestFileSourceCollectionOneDir(TestSourceCollection):
 
     def test_finding_singlefile(self):
         ex = random.choice(examples.examples)
         maindir = ['LDP', 'LDP', 'howto']
         reldir, absdir = self.mkdir_components(maindir)
         _, _ = self.addfile(absdir, ex)
-        s = SourceDirs([absdir])
+        s = SourceCollection([absdir])
         self.assertEquals(1, len(s))
 
     def test_skipping_misnamed_singlefile(self):
@@ -91,16 +91,16 @@ class TestFileSourceDirsOneDir(TestSourceDirs):
         maindir = ['LDP', 'LDP', 'howto']
         reldir, absdir = self.mkdir_components(maindir)
         self.addfile(absdir, ex, ext=".mis")
-        s = SourceDirs([absdir])
+        s = SourceCollection([absdir])
         self.assertEquals(1, len(s))
 
 
-class TestInvalidSourceDirs(TestSourceDirs):
+class TestInvalidSourceCollection(TestSourceCollection):
 
     def test_validateDirs_onebad(self):
         invalid0 = os.path.join(self.tempdir, 'unique', 'rabbit')
         with self.assertRaises(IOError) as ecm:
-            SourceDirs([invalid0])
+            SourceCollection([invalid0])
         e = ecm.exception
         self.assertTrue('unique/rabbit' in e.filename)
 
@@ -108,18 +108,18 @@ class TestInvalidSourceDirs(TestSourceDirs):
         invalid0 = os.path.join(self.tempdir, 'unique', 'rabbit')
         invalid1 = os.path.join(self.tempdir, 'affable', 'elephant')
         with self.assertRaises(IOError) as ecm:
-            SourceDirs([invalid0, invalid1])
+            SourceCollection([invalid0, invalid1])
         e = ecm.exception
         self.assertTrue('affable/elephant' in e.filename)
 
     def testEmptyDir(self):
-        s = SourceDirs([self.tempdir])
+        s = SourceCollection([self.tempdir])
         import pprint
         pprint.pprint(s.__dict__)
         self.assertEquals(0, len(s))
 
 
-class TestMissingSourceDocuments(TestSourceDirs):
+class TestMissingSourceDocuments(TestSourceCollection):
 
     def test_init_missing(self):
         missing = os.path.join(self.tempdir, 'vanishing')
diff --git a/tldp/sources.py b/tldp/sources.py
index 70680cd..aa7f519 100644
--- a/tldp/sources.py
+++ b/tldp/sources.py
@@ -10,22 +10,22 @@ from .utils import logger
 from .typeguesser import guess, knownextensions
 
 
-class SourceDirs(collections.MutableMapping):
+class SourceCollection(collections.MutableMapping):
 
     def __repr__(self):
         return '<%s:(%s docs)>' % \
                (self.__class__.__name__, len(self))
 
     def __init__(self, args):
-        sourcedirs = [os.path.abspath(x) for x in args]
-        results = [os.path.exists(x) for x in sourcedirs]
+        dirs = [os.path.abspath(x) for x in args]
+        results = [os.path.exists(x) for x in dirs]
 
         if not all(results):
-            for result, sdir in zip(results, sourcedirs):
+            for result, sdir in zip(results, dirs):
                 logger.critical("Directory does not exist: " + sdir)
             raise IOError(errno.ENOENT, os.strerror(errno.ENOENT), sdir)
 
-        for sdir in sourcedirs:
+        for sdir in dirs:
             docs = dict()
             for fname in os.listdir(sdir):
                 possible = os.path.join(sdir, fname)