University College of Addis Ababa. Geophysical Observatory & Haile Sellassie I University. Geophysical Observatory. (1959). Bulletin of the Geophysical Observatory. University College Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रUniversity College of Addis Ababa. Geophysical Observatory और Haile Sellassie I University. Geophysical Observatory. Bulletin of the Geophysical Observatory. Addis Ababa: University College Press, 1959.
एमएलए (8वां संस्करण) प्रशस्ति पत्रUniversity College of Addis Ababa. Geophysical Observatory और Haile Sellassie I University. Geophysical Observatory. Bulletin of the Geophysical Observatory. University College Press, 1959.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.