Seligman, E.R.A. et al. ed creator text New York Macmillan 1967 monographic v.p. "Lib.has : V.1-2, pp696; V.3-4, pp710; V.5-6, pp713; V.7-8, pp713; V.9-10, pp652; V.11-12, pp716; V.13-14, pp676; V.15