“Notice of Incised Sculpturings on the Steatite Rock at Feideland, the Extreme North of the Mainland of Shetland, and of a Cluster of Ruined Structures Styled Picts’ Houses, on the Kaim of Isbister, Shetland”. 1877. Proceedings of the Society of Antiquaries of Scotland 12 (November): 202-6. https://doi.org/10.9750/PSAS.012.202.206.