I can't find them with that address.

Here are links to the USDA digital documents. Click the view/open PDF link near the bottom. (warning - large files, long download)

Book:
http://ddr.nal.usda.gov/dspace/handle/10113/41278

First Supplement:
http://ddr.nal.usda.gov/dspace/handle/10113/41279

Second Supplement:
http://ddr.nal.usda.gov/dspace/handle/10113/41277

BTW, Deno's discussion of germination is really interesting but for basic reference I find Tom Clothier's database more useful.

Here is a link that might be useful: Tom Clothier

Thanks for posting the URL.
The Clothier site is good also.
They differ somewhat in which seeds they cover.
Deno has a chapter on cacti and succulents,
while Clothier has a whole chapter on penstemons.
So if you don't find something on one--look to the other.
Clothier is good on trees and shrub seed germination.
Caroline