Gardner, R. D. (1978). Horatio Alger: Or, The American hero era. Arco Pub.
Lua i Stíl Chicago (17ú heag.)Gardner, Ralph D. Horatio Alger: Or, The American Hero Era. New York: Arco Pub, 1978.
Lua MLA (9ú heag.)Gardner, Ralph D. Horatio Alger: Or, The American Hero Era. Arco Pub, 1978.
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