Ronald E. Emmerick, A Guide to the Literature of Khotan, Second Edition Thoroughly Revised and Enlarged.

Ruben Habito, Originary Enlightenment: Tendai Hongaku Doctrine and Japanese Buddhism.

An updated version is available: Yasuhiro Sueki, Bibliographical Sources for Buddhist Studies from the Viewpoint of Buddhist Philology, PDF ed.

Journal of the International College for Postgraduate Buddhist Studies, vol. XXI