He also produced books giving the text with notes of the works of a number of mediaeval poets such as Dafydd ap Gwilym and others in 1914 and Iolo Goch in 1925 with colleagues.
Tamén redactou libros que daban o texto con notas das obras dun número de poetas galeses medievais, como Dafydd ap Gwilym e outros en 1914 e Iolo Goch en 1925 xunto con outros colegas.