1. TheseRendiconti 2, 1 1952, 1–16. 0252 0101 V 2
2. loc. cit. TheseRendiconti, (20) and (22).
3. loc. cit. TheseRendiconti, (25); for the definition ofI(q), see (22).
4. loc. cit. TheseRendiconti, proof of lemma 3.
5. Regular Polytopes (London, 1948), 130.