Maxwell, C. R. (1921). The selection of textbooks. Houghton Mifflin company.
Lua i Stíl Chicago (17ú heag.)Maxwell, Charles Robert. The Selection of Textbooks. Boston, New York [etc.]: Houghton Mifflin company, 1921.
Lua MLA (9ú heag.)Maxwell, Charles Robert. The Selection of Textbooks. Houghton Mifflin company, 1921.
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