@article{FPM_2008_14_7_a6,
     author = {V. Gould and A. V. Mikhalev and E. A. Palyutin and A. A. Stepanova},
     title = {Model-theoretic properties of free, projective, and flat $S$-acts},
     journal = {Fundamentalʹna\^a i prikladna\^a matematika},
     pages = {63--110},
     publisher = {mathdoc},
     volume = {14},
     number = {7},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FPM_2008_14_7_a6/}
}