ISBN 1-57230-116-3* Kugelmann, Robert., "Psychology and Catholicism: Contested Boundaries", Cambridge University Press, 2011 ISBN 1-107-00608-2*Levin, J., "God, Faith and Health: Exploring the Spirituality-Health Connection", New York, Wiley, 2001.
ISBN 978-09820757-2-2* Kugelmann, Robert., "Psychology and Catholicism: Contested Boundaries", Cambridge University Press, 2011 ISBN 1-107-00608-2*Levin, J., "God, Faith and Health: Exploring the Spirituality-Health Connection", New York, Wiley, 2001.