@article{JRAM_1989__399_153156,
     author = {Ming-Chit Liu and Kai-Man Tsang},
     title = {On pairs of linear equations in three prime variables and an application to {Goldbach's} problem.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {109--136},
     publisher = {mathdoc},
     volume = {399},
     year = {1989},
     zbl = {0667.10030},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1989__399_153156/}
}