How are co-authors sorted?
Co-authors are ranked by their own lifetime peer-reviewed citation count, not by the number of joint papers with Jiahuai Han. A frequent collaborator with modest citation impact may rank below a highly cited collaborator with fewer shared publications.
What do A pos and C pos mean?
The # column is the rank of each listed entry for Jiahuai Han — rank 1 means this entry is where Jiahuai Han has the most articles or citations. A pos and C pos show the reciprocal: the position of Jiahuai Han within that entry's own ranked list, by articles and citations respectively. A low value means Jiahuai Han is among the most prominent contributors for that entry.
