Cowen, P., Parry-Billings, M., & Newsholme, E. (1989). Decreased plasma tryptophan levels in major depression.
芝加哥风格引文Cowen, P., M. Parry-Billings, 与 E. Newsholme. Decreased Plasma Tryptophan Levels in Major Depression. 1989.
MLA引文Cowen, P., et al. Decreased Plasma Tryptophan Levels in Major Depression. 1989.
警告：这些引文格式不一定是100％准确.