Gumplowicz, L., & Horowitz, I. L. (1963). Outlines of sociology ([2nd English language ed.].). Paine-Whitman.
Lua i Stíl Chicago (17ú heag.)Gumplowicz, Ludwig, agus Irving Louis Horowitz. Outlines of Sociology. [2nd English language ed.]. New York: Paine-Whitman, 1963.
Lua MLA (9ú heag.)Gumplowicz, Ludwig, agus Irving Louis Horowitz. Outlines of Sociology. [2nd English language ed.]. Paine-Whitman, 1963.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.