The .cites file contains the citation graph of the corpus. Each line describes a link in the following format:
<ID of cited paper> <ID of citing paper>
Each line contains two paper IDs. The first entry is the ID of the paper being cited and the second ID stands for the paper which contains the citation. The direction of the link is from right to left. If a line is represented by "paper1 paper2" then the link is "paper2->paper1".
