1. Planar graphs without 4-cycles adjacent to triangles are DP-4-colorable (with Xiaowei Yu)
  2. 3-dynamic coloring of planar triangulations (with Y. Asayama, Y. Kawasaki, A. Nakamoto, and K. Ozeki)
  3. A Sufficient condition for DP-4-colorability (with Kenta Ozeki)
  4. A note on a Brooks' type theorem for DP-coloring (with Kenta Ozeki)
  5. Relaxed antimagic labeling of graphs bounded by maximum average degree (with Guanghui Wang and Xiaowei Yu)



  1. Cycles with two blocks in $k$-chromatic digraphs (with Ringi Kim, Jie Ma, and Boram Park), J. Graph Theory.
  2. List 3-dynamic coloring of graphs with small maximum average degree (with Boram Park), Discrete Math.



  1. Decomposition of Sparse Graphs into Forests: The Nine Dragon Tree Conjecture for $k\le2$ (with Min Chen, Alexandr Kostochka, Douglas West, and Xuding Zhu), J. Combin. Theory Ser. B., 122 (2017), 741-756.
  2. Coloring of the square of Kneser graph K(2k+r, k) (with Boram Park), Graphs Combin. 32 (2016), 1461-1472.
  3. Coloring the square of graphs whose maximum average degrees are less than 4 (with Boram Park), Discrete Math. 339 (2016), 1251-1260.
  4. Bipartite graphs whose squares are not chromatic-choosable (with Boram Park), Electron. J. Combin. 22 (2015), no. 1, Paper 46
  5. Chromatic-choosability of the power of graphs (with Young Soo Kwon and Boram Park), Discrete Appl. Math. 180 (2015), 120-125
  6. Counterexamples to the List Square Coloring Conjecture (with Boram Park), J. Graph Theory 78 (2015), no. 4, 239-247
  7. Improved bounds on the chromatic numbers of the square of Kneser graphs (with Boram Park), Discrete Math. 315 (2014), 69-74.
  8. Injectively $\Delta+1$-choosable graphs (with Won-Jin Park ), Ars Combin. 112 (2013), 449457
  9. Decomposition of Sparse Graphs into Forests and a Graph with Bounded Degree (with Alexandr Kostochka, Douglas West, Hehui Wu, and Xuding Zhu), J. Graph Theory, 74 (2013), 369391
  10. Injectively $\Delta$-choosable graphs (with Won-Jin Park), Bull. Korean Math. Soc. 50 (2013), pp. 1303-1314
  11. Dynamic coloring and list dynamic coloring of planar graphs (with Sang June Lee and Won-Jin Park), Discrete Appl. Math. 161 (2013), 2207-2212.
  12. On-line list colouring of complete multipartite graphs (with Young Soo Kwon, Daphne Liu, and Xuding Zhu), Electron. J. Combin. 19 (2012), Paper 41
  13. Graph equation for line graphs and m-step graphs (with Suh-Ryung Kim, Jung Yeun Lee, Won Jin Park, and Yoshio Sano), Graphs and Combinatorics (2012) 831-842
  14. List dynamic coloring of sparse graphs (with Won-Jin Park), Lecture Notes in Computer Science, Volume 6831 LNCS, (2011), 156-162
  15. The $2$-distance coloring of the Cartesian product of cycles using optimal Lee codes (with Jon-Lark Kim), Discrete Applied Math., 159 (2011), 2222-2228.
  16. Graphs having many holes but with small competition numbers (with Suh-Ryung Kim, Jung Yeun Lee, and Yoshio Sano), Appl. Math. Lett. 24 (2011)
  17. Injective chromatic number of graphs with low average degree (with Daniel Cranston and Gexin Yu), Algorithmica 60 (2011), 553-568
  18. Injective chromatic number of sparse graph (with Daniel Cranston and Gexin Yu), Discrete Math. 310 (2010), 29652973
  19. Identifying codes of q-ary Hamming Spaces (with Jon-Lark Kim), Bulletin of the Institute of Combinatorics and its Applications, Volume 59 (2010), 93-102
  20. On competition numbers of graphs with exactly two holes (with Suh-Ryung Kim, Jung Yeun Lee, and Yoshio Sano), ARS Combinatoria 95 (2010), 45-54.
  21. Dominating sets in triangle-free planar graphs with minimum degree at least 3 (with Douglas B. West), Discussiones Mathematicae Graph Theory, 28 (2008), 563-566
  22. Coloring the complement of an intersection graph of convex figures (with Kittikorn Nakprasit), Discrete Math. 308 (2008), 4589-4594
  23. List-coloring the Square of a Subcubic graph (with Daniel Cranston), J. Graph Theory 57 (2008), 65-87
  24. On CCE graphs of doubly partial orders (with Yoomi Rho and Suh-Ryung Kim), Discrete Applied Mathematics, 155 (2007), 971-978
  25. Coloring the complement of an intersection graph of convex figures (with Kittikorn Nakprasit, Michael Pelsmajer, and Jozef Skokan), Discrete Mathematics, 306 (2006), 2166-2173
  26. On the chromatic number of the intersection graph of convex sets in the plane (with A.V. Kostochka and K. Nakprasit), Electron. J. Combinatorics, (2004) R52
  27. On the chromatic number of the square of the Kneser graph K(2k+1, k) (with K. Nakprasit), Graphs and Combinatorics, 20 (2004), 79-90
  28. Homomorphisms from sparse graphs with large girth (with O.V. Borodin, A.V. Kostochka, and D.B. West), J. Combin. Theory Ser. B., 90 (2004), 147- 159
  29. Isometric cycles and bridged graphs (with T. Jiang and D.B. West), J. Graph Theory, 43 (2003), 161-170