Dennis D. McCarthy, Alice. K. Babcock: The length of day since 1656. In: Physics of the Earth and Planetary Interiors. Band44, 1986, S.281–292, doi:10.1016/0031-9201(86)90077-4 (englisch).
Jean Meeus: The Effect of Delta T on Astronomical Calculations. In: Journal of the British Astronomical Association. 108: 154–156, 1998 (bibcode:1998JBAA..108..154M).
Morrison L.V., Stephenson F.R.: Historical values of the Earth's clock error ΔT and the calculation of eclipses. Journal for the History of Astronomy, Bd. 35, Teil 3, Nr. 120, S. 327–336 (2004) (bibcode:2004JHA....35..327M); dieselben: Addendum: Historical values of the Earth's clock error. JHA, Bd. 36, Teil 3, Nr. 124, S. 339 (2005) (bibcode:2005JHA....36..339M).