Harman, Harry H.
Modern factor analysis
University of Chicago Press, 1968
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Hummel, James A.
Introduction to vector functions
Addison-Wesley , 1967
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Hoskins, R.F.
Generalised functions
Ellis Horwood, 1979
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Zink, Harold
Modern governments
D. Van Nostrand, 1962
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Modern movement heritage
edited by Allen Cunningham; preface by Robert Maxwell
Routledge, 1998
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