Fajzi, K., Reinhardt, V., Smith, M. D. 1989. A review of environmental enrichment strategies for singly-caged nonhuman primates. Lab Animal 18(2), 23-35.

Comprehensive literature review dealing with the following topics: a) Group housing versus single housing; b) Enrichment strategies using inanimate objects; c) Socialization with conspecifics; d) Role of animal care staff.