Methods for controlling the integrity of membrane filters for the sterilizing filtration of liquids in the production of injectable solutions a review Kagan, A.Yu; Moiseenko, L.A.; Sinitsyn, M.A. Khimiko-Farmatsevticheskii Zhurnal 24(2): 166-170 1990 https://eurekamag.com/research/032/326/032326646.php