Telescopes and spectrographs: 1.3 Refracting telescopes - OpenLearn - Open University
Design of Galilean-type telescope systems
Refracting telescope - Wikipedia
Galileo and the telescope – Explaining Science
Refracting telescope - Wikipedia
Galileo and the telescope – Explaining Science
TAMDAS | Telescopes
TELESCOPE<BR> <BR>Galilean telescope. Representation of the principle of the Galilean telescope, Stock Photo, Picture And Rights Managed Image. Pic. BSI-0227606 | agefotostock
Making a Galilean Telescope
telescope
History of Science Society -- Committee on Education