Arnold, V. A., Smith, C. B., Flood, J., & Lapp, D. (1989). Doorways. Macmillan Publishing.
Lua i Stíl Chicago (17ú heag.)Arnold, Virginia A., Carl B. Smith, James Flood, agus Diane Lapp. Doorways. New York: Macmillan Publishing, 1989.
Lua MLA (9ú heag.)Arnold, Virginia A., et al. Doorways. Macmillan Publishing, 1989.
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