Gillard, J. T. (1937). The Negro Challenges: Christianity, Communism, Catholicism. Baltimore.
Lua i Stíl Chicago (17ú heag.)Gillard, John Thomas. The Negro Challenges: Christianity, Communism, Catholicism. Baltimore, 1937.
Lua MLA (8ú heag.)Gillard, John Thomas. The Negro Challenges: Christianity, Communism, Catholicism. Baltimore, 1937.
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