[44] W. E. May, "Hugues de Berze and the mariner's compass," The Mariner's Mirror, 1953, vol. 39, no. 2, pp. 103-106.
[45] H. Balmer, Beiträge zur Geschichte der Erkenntnis des Erdmagnetismus, Aarau, 1956, p. 52.
[46] The collection is the Gami 'al Hikajat; the relevant passage being given in German translation in Balmer. op. cit. (footnote [45]), p. 54.
[47] Balmer, op. cit. (footnote [45]), p. 53.