References for Trisecting an angle
- T L Heath, A history of Greek mathematics I (Oxford, 1931).
- I Thomas, Selections illustrating the history of Greek mathematics : Vol 1 (From Thales to Euclid) (London, 1967).
- I Thomas, Greek mathematical works (London, 1939).
- Chen, Tzer-lin Proof of the impossibility of trisecting an angle with Euclidean tools, Math. Mag. 39 (1966), 239-241.
- J Delattre and R Bkouche, Why ruler and compass?, in History of Mathematics : History of Problems (Paris, 1997), 89-113.