@article{MT_1992_22_a6,
     author = {G. A. Chumakov},
     title = {The {Riemannian} metric of harmonic parametrization of geodesic quadrangles on surfaces of constant curvature},
     journal = {Matemati\v{c}eskie trudy},
     pages = {133--151},
     publisher = {mathdoc},
     volume = {22},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MT_1992_22_a6/}
}