diff --git a/README.md b/README.md
index c8e72a7..a1eb651 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ I recommend try to find mature implementations, but in case you need to customiz
 my implementation is a good start to customize it for your needs.
 
 
-## Data structure implementations
+## Data structures implemented
 
 * Binary search tree
 * Binary heap
@@ -26,10 +26,16 @@ my implementation is a good start to customize it for your needs.
     * dijkstra search
     * bfs
 * [BK-Tree](https://en.wikipedia.org/wiki/BK-tree)
-* [Prefix tree] (https://en.wikipedia.org/wiki/Trie)
+* [Prefix tree](https://en.wikipedia.org/wiki/Trie)
 
+## Links
+
+* [List of algorithms](https://en.wikipedia.org/wiki/List_of_algorithms)
+* [List of data structures](https://en.wikipedia.org/wiki/List_of_data_structures)
+* [Google Technical Development Guide](https://www.google.com/about/careers/students/guide-to-technical-development.html)
 
 ## Tests
-`tox`
+
+    tox
  
  
diff --git a/setup.py b/setup.py
index d75c113..3a02cdb 100644
--- a/setup.py
+++ b/setup.py
@@ -2,11 +2,11 @@
 
 setup(
     name='data_structures',
-    version='0.1.0',
-    packages=['structures', 'structures.tests'],
+    version='0.1.1',
+    packages=['structures'],
     url='https://github.com/prawn-cake/data_structures',
     license='MIT',
     author='Maksim Ekimovskii',
     author_email='ekimovsky.maksim@gmail.com',
-    description='Pure python data structures implementations'
+    description='Various data structures implementations in pure python'
 )
diff --git a/structures/binary_heap.py b/structures/binary_heap.py
index e1bdfd4..aa27100 100644
--- a/structures/binary_heap.py
+++ b/structures/binary_heap.py
@@ -1,11 +1,8 @@
 # -*- coding: utf-8 -*-
-import abc
 
 
 class BinaryHeap(object):
 
-    __metaclass__ = abc.ABCMeta
-
     def __init__(self, values=None):
         self._storage = values or []
 
@@ -13,9 +10,8 @@ def __init__(self, values=None):
     def storage(self):
         return self._storage
 
-    @abc.abstractmethod
     def insert(self, k):
-        pass
+        raise NotImplementedError()
 
     @classmethod
     def heapify(cls, values):
@@ -24,13 +20,11 @@ def heapify(cls, values):
             heap.insert(k)
         return heap
 
-    @abc.abstractmethod
     def remove(self, k):
-        pass
+        raise NotImplementedError()
 
-    @abc.abstractmethod
     def extract_min(self):
-        pass
+        raise NotImplementedError()
 
     def swap(self, i, j):
         swap = self.storage[i]