Howse, D. (novembro de 1986). «The Greenwich List of Observatories - a World List of Astronomical Observatories Instruments and Clocks - 1670-1850». Journal for the History of Astronomy. 17. 1 páginas. Bibcode:1986JHA....17A...1H – see page A29.
Armitage, A. (1949). «Baron von Zach and his astronomical correspondence». Popular Astronomy. 57: 326–332. Bibcode:1949PA.....57..326A
Wolfschmidt, Gudrun (1998). «Gotha - the instruments of the observatory». Acta Historica Astronomiae. 3: 89–90. Bibcode:1998AcHA....3...89W