@article{CM_1967__18_1-2_49_0,
     author = {Heins, Albert E.},
     title = {On an integral equation in diffraction theory},
     journal = {Compositio Mathematica},
     pages = {49--54},
     publisher = {P. Noordhoff N. V., Groningen},
     volume = {18},
     number = {1-2},
     year = {1967},
     mrnumber = {244716},
     zbl = {0153.14903},
     language = {en},
     url = {http://archive.numdam.org/item/CM_1967__18_1-2_49_0/}
}