Every planar graph without 4-cycles adjacent to two triangles is DP-4-colorable

Wang and Lih (2002) conjectured that every planar graph without adjacent triangles is 4-choosable. In this paper, we prove that every planar graph without any 4-cycle adjacent to two triangles is DP-4-colorable, which improves the results of Lam et al. (1999), Cheng et al. (2016) and Kim and Yu arXiv:1709.09809v1].