Eckholm, E. P. (1978). Disappearing species: The social challenge. Worldwatch Institute.
Chicago Style (17th ed.) CitationEckholm, Erik P. Disappearing Species: The Social Challenge. [Washington]: Worldwatch Institute, 1978.
ציטוט MLAEckholm, Erik P. Disappearing Species: The Social Challenge. Worldwatch Institute, 1978.
אזהרה: ציטוטים אלה לעיתים לא מדויקים ב 100%.