Elliott, Osborn
Men at the top
Harper & Brothers , 1959
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Ziglar, Zig
Steps to the top
Heinemann Asia, 1995
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Sulman, Elizabeth
Introduction to soil
Prentice-Hall, 1999
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Craig, R.F. (Robert F.)
Soil mechanics
Van Nostrand Rheinhold, 1974
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Baver, L.D. (Leonard David), 1901-
Soil physics
John Wiley & Sons, 1972
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