1. Breuil, Ch.: Schemas en groupe et module filtre, C.R. Acad. Sci. Paris Ser.I Math. 328 (1999) no.2, 93–97.
2. Bourbaki, N.: Algebre Commutative, Chapt. 8 et 9, Masson 1983.
3. Berthelot, P., Breen, L., Messing, W.,: Theorie de Dieudonne Cristalline II, Springer Lecture Notes No. 930, 1982.
4. Berthelot, P., Messing, W.,: Theorie de Dieudonne Cristalline III: Theoremes d’Equivalence et de Pleine Fidelite, in: The Grothendieck Festschrift Volume I, Birkhauser 1990.
5. Messing, W.: The crystals associated to Barsotti-Tate groups, LNM 264,Springer 1972.