Author mentions Simmons' Differential Equations with Applications and Historical Notes (1972), which is at Internet Archive:
https://archive.org/details/differentialequa0000simm/page/n6...
Author mentions Simmons' Differential Equations with Applications and Historical Notes (1972), which is at Internet Archive:
https://archive.org/details/differentialequa0000simm/page/n6...
This shows as “Borrow Unavailable” for me.
The Internet Archive lost a court case against the publishers, so many books (including all books that are still available for sale) have been (or are being) soft-removed :-/
Thank-you, you're right. Hopefully we can borrow it in the future.