Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Troff:

This text has been unreferenced on Wikipedia for a very long time. If you can't find a source, be bold and remove it!

"

Bob Morris ported it to the GE 635 architecture and called the program roff (an abbreviation of runoff).[citation needed] It was rewritten as rf for the PDP-7, and at the same time (1969), Doug McIlroy rewrote an extended and simplified version of roff in the BCPL programming language.