@article{10_1017_S0008439500030319,
     author = {Heinig, H. P.},
     title = {Systems of {Singular} {Integral} {Equations,} by {N.} {P.} {Vekua.} {Translated} by {A.} {G.} {Gibbs} and {G.} {M.} {Simmons.} {P.} {Noordhoff,} {Groningen,} 1967, 216 pages.},
     journal = {Canadian mathematical bulletin},
     pages = {246--247},
     year = {1969},
     volume = {12},
     number = {2},
     doi = {10.1017/S0008439500030319},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0008439500030319/}
}