@article{CM_1990__75_3_247_0,
     author = {Urbanowicz, Jerzy},
     title = {Connections between $B_{2,\chi }$ for even quadratic {Dirichlet} characters $\chi $ and class numbers of appropriate imaginary quadratic fields, {I}},
     journal = {Compositio Mathematica},
     pages = {247--270},
     publisher = {Kluwer Academic Publishers},
     volume = {75},
     number = {3},
     year = {1990},
     zbl = {0706.11058},
     language = {en},
     url = {http://www.numdam.org/item/CM_1990__75_3_247_0/}
}