For more information you can refer the following links:
- The memory models that underlie programming languages (http://canonical.org/~kragen/memory-models/), K. J. Sitaker
- Grok the GIL: How to write fast and thread-safe Python (opensource.com/article/17/4/grok-gil), A. Jesse Jiryu Davis
- Thread Synchronization Mechanisms in Python (http://effbot.org/zone/thread-synchronization.htm#atomic-operations), Fredrik Lundh
- Memory Management (https://docs.python.org/3/c-api/memory.html), Python Documentation
- Concurrency (jython.org/jythonbook/en/1.0/Concurrency), Jython Documentation
- Memory management in Python (anubnair.wordpress.com/2014/09/30/memory-management-in-python/), Anu B Nair