@article{IM2_2007_71_3_a3,
     author = {S. A. Gritsenko},
     title = {The {Hua} {Loo-Keng} problem on prime~numbers representable
},
     journal = {Izvestiya. Mathematics },
     pages = {477--493},
     publisher = {mathdoc},
     volume = {71},
     number = {3},
     year = {2007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2007_71_3_a3/}
}