1. Measuring Programmer Productivity and Software Quality;Arthur,1985
2. An empirical analysis of network externalities in peer-to-peer music-sharing networks;Asvanund;Information Systems Research,2004
3. Network externalities in microcomputer software: An economic analysis of spreadsheet market;Brynjolfsson;Management Science,1996
4. Cakanyildirim, M., Dalgic, T., 2002. Using demonstration to promote information goods. University of Dallas Working Paper.
5. Cheng, H.K., Liu, Y.P., 2008. Software free trial: How long is optimal? Social Science Research Network. .