Cobban, W., & Kennedy, W. (1990). Observations on the Cenomanian (Upper Cretaceous) ammonite Calycoceras (Calycoceras) obrieni Young, 1957 from Arizona and New Mexico.
芝加哥风格引文Cobban, W., 与 W. Kennedy. Observations on the Cenomanian (Upper Cretaceous) Ammonite Calycoceras (Calycoceras) Obrieni Young, 1957 from Arizona and New Mexico. 1990.
MLA引文Cobban, W., 与 W. Kennedy. Observations on the Cenomanian (Upper Cretaceous) Ammonite Calycoceras (Calycoceras) Obrieni Young, 1957 from Arizona and New Mexico. 1990.
警告：这些引文格式不一定是100％准确.