Historical clue formulations

• Math subj. with proofs — 2013-12-04
• Math. class — 2008-04-20
• Study of figures: Abbr. — 2007-02-23
• Math subj. with angles — 2006-02-06
• Points are discussed in it: Abbr. — 2005-07-08
• Euclidean subj. — 2004-07-11
• Euclid's element?: Abbr. — 2003-09-07
• Subj. with circles and such — 2003-07-28
• H.S. class — 2000-11-17