Gordon, G. and Mitchell, A. 1877. 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. Proceedings of the Society of Antiquaries of Scotland. 12, (Nov. 1877), 202–206. DOI:https://doi.org/10.9750/PSAS.012.202.206.