Raven, Peter, and George Johnson. Biology. Boston: Wm C. Brown Publishers, 1990.

Buchbaum. Animals Without Backbones. United States of America: The University of Chicago Press, 1991, pg. 125-126.

Newmark, Phillip A. and Alejandro Sanchez Alvarado. "Bromodeoxyuridine

Specifically Labels the Regenerative Stem Cells of Planarians."

Developmental Biology April 15, 2000: 142-153.

Kato, Kentaro, et al. "Dorsal and Ventral Positional Cues Required for the Onset

of Planarian Regeneration May Reside in Differentiated Cells."

Developmental Biology March 29, 2001:109-121.