- Structure of the acid-labile galactosyl phosphate-containing O-antigen of the bacterium Proteus vulgaris OX19 (serogroup O1) used in the Weil-Felix test. Senchenkova, S.N., Shashkov, A.S., Toukach, F.V., Ziolkowski, A., Swierzko, A.S., Amano, K.I., Kaca, W., Knirel YuA, n.u.l.l., Kochetkov, N.K. Biochemistry Mosc. (1997)