Statistics Department, University of Chicago. ECTA program: description for users. Mimeographed paper, 1973. (ECTA)
Feinberg, S. E. The Analysis of Cross-Classified Data. Cambridge, Massachusetts: The MIT Press, 1977. (General)
Chi-square tests: Feinberg, S. E. The Analysis of Cross-Classified Data. Cambridge, Massachusetts: The MIT Press, 1977. p. 36 (Pearson and maximum likelihood)