@article{FPM_2021_23_4_a2,
     author = {E. Bunina and K. Sosov},
     title = {Endomorphisms of the semigroup of nonnegative invertible matrices of order two over commutative ordered rings},
     journal = {Fundamentalʹna\^a i prikladna\^a matematika},
     pages = {39--53},
     publisher = {mathdoc},
     volume = {23},
     number = {4},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FPM_2021_23_4_a2/}
}