@article{IIGUM_2013_6_2_a4,
     author = {R. A. Popkov and S. V. Sudoplatov},
     title = {Operators generating {Rudin--Keisler} preorders in the class of theories with continuum many types},
     journal = {The Bulletin of Irkutsk State University. Series Mathematics},
     pages = {48--56},
     publisher = {mathdoc},
     volume = {6},
     number = {2},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IIGUM_2013_6_2_a4/}
}