Studies in Spaced and Massed Learning: I Time Period and Amount of Practice

Doré L. R. (1937). Spaced practice in a motor skill and the stimulation-maturation hypothesis. Psychol. Bull. 34, 560–561.

Hull C. L. (1933). The meaningfulness of 320 selected nonsense syllables. Amer. J. Psychol. 45, 730–734.

Starch D. (1912). Periods of work on learning. J. educ. Psychol. 3, 209–213.

Tsao J. C. (1946). Interval and practice in learning: A critical review of the problem of spaced and massed learning Unpublished.