6M.Spence, 1973b. "Competitive and Optimal Responses to Signals:An Analysis of Efficiency and Distribution," Journal of Economic Theory 7: 296- 322.
7M.Spence, 1974a. " Market Signaling: Information Transfer in Hiring and Related Screening Processes," Cambridge, Massachusetts: Harvard University Press.
8M.Spence, 1974b. "Competitive and Optimal Responses to Signals: An Analysis of Efficiency and Distribution," Journal of Economic Theory 7:296 - 332.