HP-41 Book "Programming the HP 41C/CV/CX" by Thomas Adams

[Erik-M]

I understand the frustration, it took me 10 years to find "VLF radio engineering by Watts".
Over the years I have been very good at locating rare radio books, my usual sources don't know anything about this particular HP41 one but I will keep my eyes open.
(Try university libraries, also in other countries, they keep these old and obscure books.)