Levitan, R. D., Shen, J. H., Jindal, R., Driver, H. S., Kennedy, S. H., & Shapiro, C. M. (2000). Preliminary randomized double-blind placebo-controlled trial of tryptophan combined with fluoxetine to treat major depressive disorder: Antidepressant and hypnotic effects.

Levitan, R D., J H. Shen, R. Jindal, H S. Driver, S H. Kennedy, and C M. Shapiro. Preliminary Randomized Double-blind Placebo-controlled Trial of Tryptophan Combined With Fluoxetine to Treat Major Depressive Disorder: Antidepressant and Hypnotic Effects. 2000.

Levitan, R D., et al. Preliminary Randomized Double-blind Placebo-controlled Trial of Tryptophan Combined With Fluoxetine to Treat Major Depressive Disorder: Antidepressant and Hypnotic Effects. 2000.