Der Jakobuskult des 12. Jahrhunderts und der "Liber Sancti Jacobi," 1984: title page (Klaus Herbers)

Liber Sancti Jacobi, 1998: title page verso (Klaus Herbers) cover (K. Herbers)

Geschichte des Papsttums im Mittelalter, 2012: title page (Klaus Herbers) jacket (born 1951; professor of medieval history at Universität Erlangen/Nürnberg)

Regesta pontificum Romanorum ab condita ecclesia ad annum post Christum natum MCXCVIII. Tomus primus, 2016: title page (sub auspiciis Nicolai Herbers)

Friedrich-Alexander-Universität Erlangen-Nürnberg, Lehrstuhl für Mittelalterliche Geschichte und Historische Hilfswissenschaften website, viewed September 6, 2017: link to Personen page (Prof. Dr. Klaus Herbers, Lehrstuhlinhaber; born January 5, 1951, in Wuppertal-Elberfeld; received his doctorate in 1980 from the Technische Universität Berlin; joined the faculty at Erlangen-Nürnberg in 1998; coordinating editor of Regesta pontificum Romanorum ab condita ecclesia ad annum post Christum natum MCXCVIII) http://www.mittelalter.geschichte.uni-erlangen.de/cms/personen/klaus-herbers.php

Caminaron a Santiago : relatos de peregrinaciones al fin delmundo, 1999: title page (Klaus Herbers) of cover