Porcine Detection on Anti-Covid 19 Immunity Gelatin Capsules Sold at Market X in North Surabaya Using Quartz Crystal Microbalance (QCM) Sensors - Syukrianto, Syukrianto; Umarudin, Umarudin; Madurani, Kartika; Kurniawan, Fredy (Indonesian Journal of Chemical Science, 2021)