During his 29 years in Cardiff he spent a year at each of the universities of Würzburg, Freiburg (as an Alexander von Humboldt Fellow), and Vienna, and has lectured extensively in both Eastern and Western Europe, Russia and North America on mathematics, apologetics, and the exposition of scripture.
Selama 29 tahun di Cardiff ia meluangkan waktu setahun untuk setiap universitas di Würzburg, Freiburg (sebagai seorang "Alexander von Humboldt Fellow") dan Vienna serta sering memberikan kuliah di Eropa Barat dan Timur, Rusia dan Amerika Utara mengenai matematika, apologetika dan eksposisi Alkitab.