Ecological-Economic Modeling in the Cache River Basin: The Challenge of Ecological-Economic Modeling on a Watershed Basin, a Potential Framework for Sustainable Development; Final Report, Submitted to the Illinois Field Office of the Nature Beck Roger Innbundet / 2018 / Engelsk
Religion of the Mithras Cult in the Roman Empire Mysteries of the Unconquered Sun Beck Roger Innbundet / 2006 / Engelsk
Ecological-Economic Modeling in the Cache River Basin: The Challenge of Ecological-Economic Modeling on a Watershed Basin, a Potential Framework for Sustainable Development; Final Report, Submitted to the Illinois Field Office of the Nature Beck Roger Heftet / 2018 / Engelsk
Religion of the Mithras Cult in the Roman Empire Mysteries of the Unconquered Sun Beck Roger Heftet / 2007 / Engelsk
True Light Ordinary People on the Extraordinary Spiritual Path of Sukyo Mahikari Banerjee Brown, Leena Heftet / 2021 / Engelsk
