@article{FPM_2002_8_2_a17,
     author = {V. Yu. Popov},
     title = {On positive theories of semigroup varieties and pseudovarieties},
     journal = {Fundamentalʹna\^a i prikladna\^a matematika},
     pages = {631--635},
     publisher = {mathdoc},
     volume = {8},
     number = {2},
     year = {2002},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FPM_2002_8_2_a17/}
}