ZHANG, GUIZHI; AN, YONGHONG; FENG, TAO. The intersection problem for PBD(4, 7∗)1. Utilitas Mathematica , [S. l.], v. 107, 2018. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/1331. Acesso em: 26 may. 2026.