1. Ebbinghaus, H. 1913.Memory, Edited by: Ruger, H. A. and Bussenius, C. E. viii+123New York: Teach. Coll., Columbia Univ.
2. Evans, C. L. 1930.Recent advances in physiology (), 4th ed., xii+446Philadelphia: Blakiston's.
3. Remote associative tendencies in serial learning.