WATTLES, Jeffrey. Living in truth, beauty, and goodness : values and virtues. Eugene, Oregon : Cascade Books, [2016]. ©2016. 1 online zdroj (220 stran). Dostupné na internetu: <https://research.ebsco.com/linkprocessor/plink?id=a12717d9-41e9-3a00-89c0-211a50d3bafe> ISBN 978-1-4982-3972-1.