National Research Council (U.S.). Committee on Preservation of Historical Records. Preservation of historical records.
استشهاد بنمط شيكاغوNational Research Council (U.S.). Committee on Preservation of Historical Records. Preservation of Historical Records.
MLA استشهادNational Research Council (U.S.). Committee on Preservation of Historical Records. Preservation of Historical Records.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.