@article{MZM_2008_84_2_a9,
     author = {V. E. Firstov},
     title = {A {Special} {Matrix} {Transformation} {Semigroup} of {Primitive} {Pairs} and the {Genealogy} of {Pythagorean} {Triples}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {281--299},
     publisher = {mathdoc},
     volume = {84},
     number = {2},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2008_84_2_a9/}
}