Journal of the London Mathematical SocietyVolume s2-13, Issue 3 p. 543-556 Notes and Papers On the Deficiency Indices of Powers of Real 2nth-Order Symmetric Differential Expressions W. D. Evans, W. D. Evans Department of Pure Mathematics, University College, Cardiff, WalesSearch for more papers by this authorA. Zettl, A. Zettl Department of Mathematical Science, Northern Illinois University, De Kalb, Illinois, U.S.A.Search for more papers by this author W. D. Evans, W. D. Evans Department of Pure Mathematics, University College, Cardiff, WalesSearch for more papers by this authorA. Zettl, A. Zettl Department of Mathematical Science, Northern Illinois University, De Kalb, Illinois, U.S.A.Search for more papers by this author First published: August 1976 https://doi.org/10.1112/jlms/s2-13.3.543Citations: 10AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volumes2-13, Issue3August 1976Pages 543-556 RelatedInformation