Add citations (#6)

resources/bibliography.bib

@@ -53,4 +53,20 @@ @Electronic{bibulous
   timestamp = {09.09.2016},
 }
 
+@Book{Anderson1995,
+  title     = {An Introduction to Neural Networks},
+  publisher = {MIT Press},
+  year      = {1995},
+  author    = {Anderson, James},
+}
+
+@Electronic{Stanley2002,
+  author       = {Stanley, Kenneth},
+  year         = {2002},
+  title        = {Evolving Neural Networks through Augmenting Topologies},
+  organization = {Massachusetts Institute of Technology},
+  url          = {http://nn.cs.utexas.edu/downloads/papers/stanley.ec02.pdf},
+  timestamp    = {11.9.2016},
+}
+
 @Comment{jabref-meta: databaseType:bibtex;}

sections/what is a neural network.tex

@@ -7,7 +7,7 @@ \section{What is a neural network?}
 
 Connections connect neurons to each other. Each connection has a weight, which determines how weak or strong the connection is.
 
-The neurons are typically organized into layers. The first is referred to as the input layer and the last one as the output layer. The remaining layers are called hidden layers.
+The neurons are typically organized into layers. The first is referred to as the input layer and the last one as the output layer. The remaining layers are called hidden layers. \cite{Anderson1995}
 
 Here is a basic example of a neural network:
 
@@ -27,7 +27,7 @@ \section{What is a neural network?}
 
 Each connection is represented as an arrow and has an associated weight. Every neuron is connected to all neurons in the previous and in the next layer.
 
-The network above has 9 weights. This is the genome, which is used to store the configuration of a network.
+The network above has 9 weights. This is the genome, which is used to store the configuration of a network.\cite{Stanley2002}
 
 For simple networks, you can also write down the inputs and the corresponding outputs.