Chapman and Hall, London. Dawkins, M.S. 1990. Spatially enhanced caging for laboratory rats at high density. Some theoretical and observed relationships of fixed and portable spacing behavior of animals. Applied Animal Ethology 201-214.
Research approaches to improve the technical welfare and the environment of laying hens.
Use of cage space by guinea pigs. The Animal Welfare Information Center U.S. Department of Agriculture Agricultural Research Service National Agricultural Library 10301 Baltimore Ave.