Middleton, T. C. (1907). State of Geographical Knowledge at the Time of the Discovery of America, A.D. 1492. Delaware Co., Pa..
Lua i Stíl Chicago (17ú heag.)Middleton, Thomas C. State of Geographical Knowledge at the Time of the Discovery of America, A.D. 1492. Delaware Co., Pa., 1907.
Lua MLA (8ú heag.)Middleton, Thomas C. State of Geographical Knowledge at the Time of the Discovery of America, A.D. 1492. Delaware Co., Pa., 1907.
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