Shutts, G. C., & Weir, W. W. (1927). Agricultural arithmetic. Webb Pub. Co..
Lua i Stíl Chicago (17ú heag.)Shutts, George C., agus Wilbert Walter Weir. Agricultural Arithmetic. St. Paul, Minn.: Webb Pub. Co., 1927.
Lua MLA (8ú heag.)Shutts, George C., agus Wilbert Walter Weir. Agricultural Arithmetic. Webb Pub. Co., 1927.
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