4Collins and Maydew and Weiss(1997), changes in the value- relevance of earnings and bood values over the past forty years, journal of accounting and economics 24(1997),39-67,PP. 52.
5Ohlson, J. , 1995, earnings, book values, and dividends in equity valuation, Contemporary accounting research, Spring: 661 - 687.
6Barth,E.M.,Clinch,G.Revalued Financial,Tangible,and Intangible Association with Share Price and Non-Market-Based Value Estimates[J].Journal of Accounting Research (Supplement),1998:199~ 233.
7Aboody,D.,Lev B.The Value Relevance of Intangibles:The Case of Software Capitalization[J].Journal of Accounting Research,1998,(36):161-191.
8Ely,K,Waymire G.Intangible Assets and Stock Prices in the Pre -SEC Era[J].Journal of Accounting Reaearch,1999,(37):17-44.
9Chan, Louis K. C. , Josef Lakonishok and Theodore Sougiannis. The Stock Market Valuation of Research and Development Expenditures[J]. Journal of Finance, 2001, (6) : 2431- 2456.
10David Aboody and Baruch Lev. The Value - Relevance of Intangibles: The Case of Software Capitalization [ J ]. Journal of Accounting Research, 1998, (36) : 161 - 204.
8Lev,B.,On the usefulness of earnings and earnings research ; lessons and directions form two decades of empirical research [ J] . Journalof Accounting Research, 1989(27 ).
9Lev, B.,and P. Zarowin, The Bundaries of Financial Reporting and How to Extend Them [ J]. Journal of Accounting Research.,1999.
10Kjell Henry Knivsfla. Accounting for Intangible Assets: The Informational Relevance of Deferred Charges [ Z]. Bergen, Norway: Founda-tion for Research in Economics and Business Administration, 1999.