His dissertation was later published as Spanish Romanesque Architecture of the Eleventh Century (Oxford University Press, 1941). In 1932, he did the first full transcription of the medieval Codex Calixtinus in Santiago de Compostela.
After completing his dissertation, which was published as "Spanish Romanesque Architecture of the Eleventh Century" by Oxford University Press in 1941, he undertook the first full transcription of the medieval Codex Calixtinus in Santiago de Compostela in 1932.