What do A pos and C pos mean?
The # column is the rank of each listed entry for Eliezer Van Allen — rank 1 means this entry is where Eliezer Van Allen has the most articles or citations. A pos and C pos show the reciprocal: the position of Eliezer Van Allen within that entry's own ranked list, by articles and citations respectively. A low value means Eliezer Van Allen is among the most prominent contributors for that entry.