Woollard, G. P. (1967). International gravity measurements. University of Wisconsin, Geophysical and Polar Research Center.
Chicago-viite (17. p.)Woollard, George P. International Gravity Measurements. Wisconsin: University of Wisconsin, Geophysical and Polar Research Center, 1967.
MLA-viite (9. p.)Woollard, George P. International Gravity Measurements. University of Wisconsin, Geophysical and Polar Research Center, 1967.
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