Robertson, John: A Treatise Of Such Mathematical Instruments As are usually put into a Portable Case, Containing their various Uses in Arithmetic, Geometry, Tringonometry, [...] : With a short Account Of the Authors who have treated on the Proportional Compasses And Sector : To which is now added An Appendix; Containing, the Description [...]. London : Printed for T. Heath and J. Nourse ...; J. Hodges .., and J. Fuller ..., MDCCLVII