écliptique
1969 / Ptolemy's Determination of the Obliquity of the Ecliptic / John P. Britton / Centaurus 14 (1969) p. 29 [doi]
1983 / Eratosthenes' Ratio for the Obliquity of the Ecliptic / David H. Fowler ; Dennis Rawlins / Isis 74 (1983) p. 556 [lien]
1993 / Le mouvement apparent du Soleil parmi les constellations / J.-P. Rosenstiehl / Bulletin de l'Union des Physiciens 759 (1993) p. 1543 [lien]
2002 / Eratosthenes, Hipparchus, and the obliquity of the ecliptic / Alexander Jones / Journal for the History of Astronomy 33 (2002) p. 15 [lien]