Lecocq, C., & Sedgwick, A. B. (1876). The twin sisters: Comic operetta in one act. De Witt.
Lua i Stíl Chicago (17ú heag.)Lecocq, Charles, agus Alfred B. Sedgwick. The Twin Sisters: Comic Operetta in One Act. New York: De Witt, 1876.
Lua MLA (8ú heag.)Lecocq, Charles, agus Alfred B. Sedgwick. The Twin Sisters: Comic Operetta in One Act. De Witt, 1876.
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