ScienceDirect (Online service). (1971). Discrete mathematics. North-Holland Pub. Co..
芝加哥风格引文ScienceDirect (Online service). Discrete Mathematics. Amsterdam: North-Holland Pub. Co., 1971.
MLA引文ScienceDirect (Online service). Discrete Mathematics. North-Holland Pub. Co., 1971.
警告：这些引文格式不一定是100％准确.