Dennis M. Ritchie, "The Development of the C Language", 1993. Quote: "The B compiler on the PDP-7 did not generate machine instructions, but instead 'threaded code' ..."
Busby, Jonathan (2018-09-07). "The RPL inner loop explained". The Museum of HP Calculators. Archived from the original on 2023-08-03. Retrieved 2019-12-27.
Busby, Jonathan (2018-09-07). "The RPL inner loop explained". The Museum of HP Calculators. Archived from the original on 2023-08-03. Retrieved 2019-12-27.