Morrison, D. G., Campbell, D. T., and Wolins, L.A FORTRAN program for evaluating internal consistency and single-factored-ness in sets of multi-level attitude items. Evanston, Ill.: Vogelback Computer Center, Northwestern University, 1965 , revised 1967. (Distributed as ATTANAL NUCC0048)
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Werner, R.A FORTRAN program for Guttman and other scalogram analyses. Evanston, Ill.: Vogelback Computer Center, Northwestern University, 1965 , revised 1967. (Distributed as GUTTSCL NUCC0115).