Arcturus IF Project - Github Site
R47 Calc Owner's Manual Releases
Tangent's R47 Beginner's Journey
Web Based R47 Calculator Simulator
Swiss Micros DM32 User's Manual
HP Calc - Software and Information Archive
Hewlett-Packard Calculator Museum
SDF's Interim Computer Museum - (Retro Computers)
Astronomy Calculations With a Pocket Calculator (pdf)
