- Graph Theory

- Connectivity for k-knitted graphs and for minimal counterexamples to Hadwiger's Conjecture (with K. Kawarabayashi) to appear in J. of Comb. Theory Ser. B
- Linkage for the diamond and the path with four vertices (with Mark Ellingham and Mike Plummer) accepted by Journal of Graph Theory
- Implications among linkage properties in graphs (with Q. Liu and D. West), J. Graph Theory 60 (2009), no. 4, 327--337.
- On Ore-type degree condition for a graph to be $H$-linked (with A. Kostochka), J. Graph Theory, 58 (2008) 14-26.
- Minimum degree conditions for $H$-linked graphs (with A. Kostochka), Disc. Appl. Math 156 (2008) 1542-1548.
- A lower bound for minimum degree in $H$-linked graphs (with R. Gould, A. Kostochka), SIAM J. on Discrete Math (SIDMA) 20 (2006), 829-840.
- On Degree Conditions for a Graph to be $k$-linked (with K. Kawarabayashi, A. Kostochka), Combinatorics, Probability and Computing 15 (2006), 685--694.
- An extremal problem for $H$-linked graphs (with A. Kostochka), J. Graph Theory 50 (2005), 321-339.
- Graphs containing every 2-factor.pdf (with A. Kostochka) to appear in Graphs and Combinatorics
- Ore-conditions implying 2-factors consisting of short cycles (with A. Kostochka), Discrete Mathematics 309 (2009) 4762-4771.
- Extremal graph packing problems: Ore-type versus Dirac-type (with H. Kierstead and A. Kostochka), London Math. Soc. Lecture Note Ser., 365, Cambridge Univ. Press, Cambridge, 2009.
- Packing of graphs with small product of sizes (with A. Kostochka), J. Combin. Theory Ser. B 98 (2008), no. 6, 1411--1415.
- On a graph packing conjecture of Bollob\'as, Eldridge and Catlin (with H. Kaul, A. Kostochka), Combinatorica 28 (2008), no. 4, 469--485.
- An Ore-type analogue of the Sauer-Spencer Theorem (with A. Kostochka), Graphs and Combinatorics 23 (2007) no 4, 419-424.
- Ore-type graph packing problems (with A. Kostochka), Combinatorics, Probability and Computing 16 (2007), 167-169.
- Planar graphs without 4- or 5-cycles are $(3,0,0)$-colorable (with O. Hill, J. Xu, D. Smith, Y. Wang), submitted.
- A note on strong edge-coloring of 2-degenerate graphs (with R. Luo)
- Strong edge-colorings of $k$-degenerate graphs submitted.
- A relaxation of Steinberg's Conjecture (with Owen Hill) to appear in SIAM J. of Disc. Math.
- Linear colorings of subcubic graphs (with Chun-Hung Liu) submitted.
- Linear Choosability of Sparse Graphs (with Dan Cranston) Discrete Math., 311 (2011), 1910--1917.
- Injective colorings of graphs with low average degree (with Dan Cranston and Seog-Jin Kim) Algorithmica 60 (2011) 553-568.
- Equitable defective coloring of sparse planar graphs (with Lee Williams and Jennifer Vandenbussche) Disc. Math., 312 (2012), no. 5, 957--962.
- Equitable coloring sparse planar graphs (with Rong Luo, Jean-Sebastien Sereni, and Chris Stephen) SIAM J. Discrete Math 24 (2010) 1572-1583.
- Injective colorings of sparse graphs (with Dan Cranston and Seog-Jin Kim) Discrete Math. 310 (2010) 2965-2973.
- First-Fit chromatic numbers of planar and random graphs (with J. Balogh, S. Hartke, and Q. Liu), SIAM J. on Discrete Mathematics 22 (2008), 887-900.
- An inequality for the group chromatic number of a graph (with Hong-Jian Lai and Xiangwen Li), Discrete Mathematics, 307 (2007) 3076-3080.
- An Extremal problem on group connectivity of graphs (with R. Luo, R. Xu) European J. Combinaotorics, 33 (2012) 6, 1078--1085
- Ore-condition and $Z_3$-connectivity (with Rong Luo, Rui Xu and Jianhua Yin), European J. of Combinatorics 29 (2008) 1587-1595.
- Nowhere-zero $Z_3$-flows through $Z_3$-connectivity (with M. DeVos, R. Xu), Discrete Mathematics 306 (2006), 26-30.
- M-degrees and $C_4$-free planar graphs (with O. Borodin, A Kostochka, and N. Sheikh), J. Graph Theory 60 (2009), no. 1, 80--85.
- Planar graphs with girth $9$ can be edge-partitioned into a forest and a matching (with O. Borodin, A Kostochka, and N. Sheikh), European J. of Combinatorics, 29 (2008) 1235-1248.
- Perfect partition of some regular partite graphs, (with Jeff Soosiah and C.-K. Li), submitted.
- Toward Efficient Channel Hopping for Communication Rendezvous in Dynamic Spectrum Access Networks (Y. Zhang, G. Yu, Q. Li, H. Wang, G. Zhu, and B. Wang), submitted to IEEE/ACM Transactions on Networking.
- New bounds on the minimum density of a vertex identifying code for the infinite hexagonal grid (with Ari Cukierman)
- Permutations as product of parallel transpositions (with Chase Albert, Chi-Kwong Li, and Gil Strang)SIAM J. Disc. Math., 25 (2012), 1412--1417.
- ETCH: EfficienT Channel Hopping for Communication Rendezvous in Dynamic Spectrum Access Networks. (with Yifan Zhang, Qun Li, and Baosheng Wang). IEEE Infocom, Shanghai, China, April 10-15, 2011.
- A new bound on the density of vertex identifying codes for the infintie hexagonal grid (with Dan Cranston) Electronic Journal of Combinatorics 16 (2009) no 1, research paper 113. (16 pages)
- On the pagenumebr of k-trees (with J. Vandenbussche, D.B. West), SIAM J. on Discrete Mathematics 23 (2009) 1455-1464.
- Hamiltonian connectedness in 3-connected line graphs. (with H.-J. Lai, Y. Shao and M. Zhan), Discrete Appl. Math. 157 (2009), no. 5, 982--990.
- On the minimum 2-wide wide diameter of Cylces with Chords (with B. Liu and X. Hou) Operation Research Transactions (Chinese) 13 (2009) 1-5.
- On extremal matrices of second large exponent by boolean rank (with B. Liu and L. You), Linear Algebra and Application 422 (2007) 186-197.
- On maximal $(k,b)$-free sets of integers and its spectrum (with B. Liu and L. You), Austra.. J. Combin. 23 (2001), 211--215.