ProQuest. (2004). ProQuest Science Journals. USA: Umi company.
Trích dẫn kiểu ChicagoProQuest. ProQuest Science Journals. USA: Umi company, 2004.
ציטוט MLAProQuest. ProQuest Science Journals. USA: Umi company, 2004.
אזהרה: ציטוטים אלה לעיתים לא מדויקים ב 100%.