Primary source

Von Hahn-Hahn 1844 (Online Access via archive.org):

<https://archive.org/details/orientalischebri03hahn_0/page/166/mode/2up> (Accessed 01.03.2022)

Literature

Newton 1980

Newton, R. R., The Sources of Eratosthenes Measurement of the Earth, in: Quarterly Journal of the Royal Astronomical Society, Vol. 21 (1980) 379. online available.

Wilson 1991

Wilson, K., “An Encyclopedia of continental women writers”, New York and London: Garland Publishing, Vol. 1 (1991) 523–524. online available.

Pictures

Fig. 1: <https://commons.wikimedia.org/wiki/File:Ida_Gr%C3%A4fin_von_Hahn-Hahn.jpg> (Accessed: 01.03.2022).