For Martin Hengel’s complete bibliography, see:

2010. Jörg Frey, “Gesamtbibliographie Martin Hengel 1959-2010.” Pages 557-609 in Martin Hengel. Theologische, historische und biographische Skizzen. Kleine Schriften VII. Edited by Claus-Jürgen Thornton with an appreciation and complete bibliography by Jörg Frey. WUNT 253.

See also the essays on Martin Hengel and the six translated essays by Martin Hengel in the following volume:

2012. Michael Bird and Jason Maston, eds. Earliest Christian History: History, Literature, and Theology: Essays from the Tyndale Fellowship in Honour of Martin Hengel. Tübingen: Mohr Siebeck, 2012.

Finally, see the following two volumes, which also appeared after the publication of Frey’s bibliography:

2019. Hengel, M., and A. M. Schwemer. Jesus and Judaism. Translated by W. Coppins. Edited by W. Coppins and S. Gathercole. BMSEC 7. Waco, Tex.: Baylor University Press.

2019. Hengel, M., and A. M. Schwemer. Geschichte des frühen Christentums. Vol. 2: Das Urgemeinde und das Judenchristentum. Tübingen: Mohr.

For Martin Hengel’s English publications, see here.