1. https://www.cs.toronto.edu/~kriz/cifar.html. https://www.cs.toronto.edu/~kriz/cifar.html.
2. http://benchmark.ini.rub.de/'section=gtsrb. http://benchmark.ini.rub.de/'section=gtsrb.
3. http://vis-www.cs.umass.edu/lfw/. http://vis-www.cs.umass.edu/lfw/.