Unless you're after the ANSI standard in particular, I believe the same content is in ECMA-78 and a few of the other ECMA standards (freely downloadable from their site.)
Whoah. [insert Keanu Reeves memegif]
Thanks, I need the older 48 TPI standard, but I will now search ECMA. But I can't find any reference to 48 TPI media there. Apparently they are withdrawn.
These international standards bodies are not something I'm familiar with, there are so many.
But it's awesome to have this alternative source if I ever need it. I might for the weird 100 TPI drive I have here.
OTOH my local provincial library just let me know that they managed to do an inter-library loan for the X3 stuff! Only "on site" reference but I can sit down with them.