selected publications academic article Wan, G. G., & Liu, Z. (2010). Knowing your users: the value of article database usage analysis. Learned Publishing. 23(3), 225-236. Wan, G. G., & Liu, Z. (2008). Content-based information retrieval and digital libraries. Information Technology and Libraries. 27(1), 41-47. Liu, Z., & Wan, G (2007). Scholarly Journal Articles on Open Access in LIS Literature: A Content Analysis. Chinese Librarianship. 23. Liu, Z. (2007). Scholarly communication in educational psychology: a journal citation analysis. Collection Building. 26(4), 112-118. Liu, Z., & Wang, C. Z. (2005). Mapping interdisciplinarity in demography: a journal network analysis. Journal of Information Science. 31(4), 308-316. Liu, Z. (2005). Visualizing the intellectual structure in urban studies: A journal co-citation analysis (1992-2002). Scientometrics: an international journal for all quantitative aspects of the science of science, communication in science and science policy. 62(3), 385-402. Liu, Z., & Yang, Z. (2004). Factors influencing distance-education graduate students' use of information sources: A user study. The Journal of Academic Librarianship. 30(1), 24-35. Wang, C., & Liu, Z (2003). Distance education: basic resources guide. Collection Building. 22(3), 120-130. Liu, Z., & Wan, G Comparing Journal Impact Factor and H-type Indices in Virology Journals