Carwardine, M. The Guiness Book of Animal Records. 1995. “Spider silk is the strongest of all natural and man-made fibres. It is even stronger than steel.”: the dragline of a European garden spider (Araneus diadematus).
Chambers, S. M. and S. Jahrsdoerfer. 1988. Endangered and threatened wildlife and plants; Final rule to determine five Texas cave invertebrates to be endangered species. Federal Register 53(180): 36029-36033.