1. Aarts, J., Fokking, R., and Kruijtzer, G. (2001). Morphic numbers. pages 56–58.
2. Boeyens, J. C. and Thackeray, J. F. (2014). Number theory and the unity of science. 110:1–2.
3. Bronshtein, I., Semendyayev, K., Musiol, G., and M++hlig, H. (2004). Handbook of Mathematics. Springer; 4th edition.
4. Calladine, C. R. (1989). Theory of Shell Structures. Cambridge University Press.
5. de Spinadel, V. W. and Buitrago, A. R. (2009). Towards van der laans plastic number in the plane. 13:163–175.