DCG	Discounted Cumulative Gain [55]
ECP	Empirical Conditional Probability
EIR	Euclidean Item Recommender [6]
FC	Model from Section 3.5 followed by similarity
FD	Model from Section 3.4 followed by similarity
GRU	Gated Recurrent Unit [17]
Gru4Rec	Recommender algorithm using GRU units [7]
KDE	Kernel Density Estimation
RNN	Recurrent Neural Network