Harman, Harry H.
Modern factor analysis
The University of Chicago Press, 1976
 Buku Teks SO
Whittaker, E.T.
A course of modern analysis : an introduction to the general theory of infinite processes and of analytic functions; with an account of the principal trancendental functions / E.T. Whittaker, G.N. Watson
Cambridge University Press, 1965
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Edwards, Allen L.
Statistical analysis
Rinehart and Winston , 1958
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Studies in item analysis and prediction
edited by Herbert Solomon
Stanford University Press, 1961
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Lewis, Edward E.
Methods of statistical analysis in economics and business
Houghton Mifflin, 1963
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