T. G. Repp, “Letter from Thorleif Gudmundson Repp, A.M., F.S.A. Sc., to the Hon. Montstewart Elphinstone, Honorary Member S.A.Sc., regarding the Runic Inscription on the Monument at Ruthwell”, arch-scot, vol. 4, pp. 327–336, Nov. 1858.