Payont Sinsuwonkwat, and Cherngchai Chumtarusmi. 1991. “The BHK21C13 Suspension Cells Culture in 5% PEG Treated Serum for FMD Virus and Vaccine Production”. Agriculture and Natural Resources 25 (2). Bangkok, Thailand:200-205. https://li01.tci-thaijo.org/index.php/anres/article/view/241966.