- https://towardsdatascience.com/lets-code-a-neural-network-in-plain-numpy-ae7e74410795
- https://www.geeksforgeeks.org/implementation-of-neural-network-from-scratch-using-numpy/
- https://towardsdatascience.com/animated-rnn-lstm-and-gru-ef124d06cf45
- https://towardsdatascience.com/implementing-recurrent-neural-network-using-numpy-c359a0a68a67
- http://aikorea.org/blog/rnn-tutorial-1/
- https://aikorea.org/blog/rnn-tutorial-2/
- http://www.wildml.com/2015/09/recurrent-neural-networks-tutorial-part-1-introduction-to-rnns/
- http://www.wildml.com/2015/09/recurrent-neural-networks-tutorial-part-2-implementing-a-language-model-rnn-with-python-numpy-and-theano/