1. Bailey, G. B., Clough, C. T., Wright, W. B., Richey, J. E. & Wilson, G. V. Mem. geol. Surv. U.K. (1924).
2. Ballantyne, C. K. & Wain-Hobson, T. Scott. J. Geol. 16, 1–10 (1980).
3. Sissons, J. B. Scott. J. Geol. 13, 23–36 (1977).
4. Sissons, J. B. The Evolution of Scotland's Scenery (Oliver & Boyd, Edinburgh, 1967).
5. Gray, J. M. & Brooks, C. L. Scott. J. Geol. 8, 95–103 (1972).