@article{03718398, title = {On the block structure of PBIB designs.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {3}, year = {1980}, pages = {169-175}, doi = {10.1155/S0161171280000105}, zbl = {0458.62065}, language = {en}, url = {http://dml.mathdoc.fr/item/03718398} }
Chandak, M.L. On the block structure of PBIB designs.. International Journal of Mathematics and Mathematical Sciences, Tome 3 (1980) pp. 169-175. doi : 10.1155/S0161171280000105. http://gdmltest.u-ga.fr/item/03718398/