Spencer, E. W. (2003). Earth science: Understanding environmental systems. McGraw-Hill.
Trích dẫn kiểu ChicagoSpencer, Edgar Winston. Earth Science: Understanding Environmental Systems. McGraw-Hill, 2003.
ציטוט MLASpencer, Edgar Winston. Earth Science: Understanding Environmental Systems. McGraw-Hill, 2003.
אזהרה: ציטוטים אלה לעיתים לא מדויקים ב 100%.