To search for other ebooks on other databases you can search SOLO using the box underneath all electronic sources are clearly marked.
Max Planck Encyclopedia of Public International Law - available via SOLO. This a encyclopedia covering all public international law. It has updated articles on a number of broad topics which provides background information, links to documents, a selected bibliography and selected links to primary sources.
Human Rights: Law & Practice, Lester, Pannick & Herberg. This is available to holders of an Oxford SSO via LexisLibrary. From the homepage of Lexis Libary if you put 'Pannick' in the quick find box (use the 'find a source' field) it should come up. You can either search or browse the book.
Oxford Scholarship Online is a series of Ebooks which are available to OU members via SOLO. There are currently over 170 titles on this platform. The books are individually catalogued and so will come up on a SOLO search but if you wanted browse then if you can choose 'Law' as a subject and then Human Rights.