Approximation algorithms for some graph partitioning problems. He, G.; Liu, J.; Zhao, C. — 2000 Journal of Graph Algorithms and Applications
Nontrivial periodic solutions for strong resonance hamiltonian systems K. C. Chang; J. Q. Liu; M. J. Liu — 1997 Annales de l'I.H.P. Analyse non linéaire
A new generalization of Ostrowski type inequality on time scales. Liu, Wenjun J.; Ngô, Qúôc-Anh; Chen, Wenbing B. — 2009 Analele Ştiinţifice ale Universităţii “Ovidius" Constanţa. Seria: Matematică