Cowles, M. (1989). Echos of an era. Westminster Congregational United Church of Christ.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCowles, Margaret. Echos of an Era. Spokane, WA (S. 411 Washington, Spokane 99204): Westminster Congregational United Church of Christ, 1989.
एमएलए (8वां संस्करण) प्रशस्ति पत्रCowles, Margaret. Echos of an Era. Westminster Congregational United Church of Christ, 1989.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.