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