@article{ZNSL_1984_135_a14,
     author = {J. B. Farforovskaja},
     title = {Estimate of $\|f(A_1, A_2)-f(B_1, B_2)\|$ for a~couple of selfadjoint commuting operators.},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {175--177},
     publisher = {mathdoc},
     volume = {135},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1984_135_a14/}
}