Parker, R. A (1974). "Ancient Egyptian Astronomy". Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences276 (1257): 51–65. doi:10.1098/rsta.1974.0009. Bibcode: 1974RSPTA.276...51P.
harvard.edu
adsabs.harvard.edu
Parker, R. A (1974). "Ancient Egyptian Astronomy". Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences276 (1257): 51–65. doi:10.1098/rsta.1974.0009. Bibcode: 1974RSPTA.276...51P.