Graaff, J. d. V., & Samuelson, P. A. (1967). Theoretical welfare economics. Cambridge University Press.

Graaff, J. de V., and Paul A. Samuelson. Theoretical Welfare Economics. Cambridge ; New York, NY: Cambridge University Press, 1967.

Graaff, J. de V., and Paul A. Samuelson. Theoretical Welfare Economics. Cambridge University Press, 1967.