1990's ISBN numbers, still good?

I bought a block of ten ISBN numbers, I think it was in the 90's. It could have been in the 80's I don;t exactly remember.

For example, here is the first one, the ISBN-13 and the ISBN-10:

978-0-9844203-0-8 0-9844203-0-4

The publisher I was working with said these were no longer good, but their word is not necessarily reliable.

Anybody know?

 

I'm pretty certain ISBNs don't expire. Lemme see if I can find something to document that ...

Here you go: https://www.thebookdesigner.com/2012/01/how-to-reconstruct-old-isbns-for-use-today/

I think Joel Friedlander is a reliable source. He was a professional book designer.

 

I received a prompt response from R. R. Bowker:

Now you know.

 

Thank you very much, sir!

(It's Friday, Saturday looks to be even better, and Sunday is going to be the creme de la creme (hope I didn't botch that phrase)).

Looks like my animated GIF avatar doesn't animate...and I copied it from somewhere, so if I copied it from this website, please let me know.

 

Thank heaven for small favors. I don't pay much attention to others' avatars, but animated ones are a major annoyance to me.