GRAPHS AND COMBINATORICS, cilt.31, sa.3, ss.537-545, 2015 (SCI-Expanded)
In this paper, we will give intersection numbers for two simple 2-fold (3n, n, 3) group divisible designs. More precisely, we will develop constructions which show that there exists two simple 2-fold (3n, n, 3) group divisible designs which intersect in precisely triples for . There are some exceptions for n = 2, 3, 4.