Walking and Trekking in the Sierra Nevada 38 walks, scrambles and multi-day traverses Hartley Richard Heftet / 2022 / Engelsk
Guide to Printed Sources for the History of the Eastern Goldfields Region of Western Australia Hartley Richard G. Heftet / 2000 / Engelsk
Snapshots of Research Readings in Criminology and Criminal Justice Hartley Richard D. Heftet / 2010 / Engelsk
