Teman-teman tolong yang punya akses kesini, terima kasih journal: J AOAC Int. 2005 Nov-Dec;88(6):1579-82. title: Solid-phase extraction of vitamins A and E from animal feeds: A substitute for liquid--liquid extraction. author : Fedder R, Plöger A. http://www.ncbi.nlm.nih.gov/pubmed/16526436
