Legal Question in Intellectual Property in California

Re: using content from a commercial source

You should be able to use any words you want, because individual words are not copyrightable. As for mentioning their name, it would be best to get permission, but if you are simply mentioning the name of the product or company, and identify it correctly as a trademark belonging to them, you should be okay. What you may NOT do is imply that your product comes from, or is endorsed by, that other company.

I would strongly advise you, though, to speak with a competent intellectual property attorney before you publish your work. The exact wording you use, or other factors, may be important.

Re: using content from a commercial source

You do need permission to use the Pimsleur name. As to the vocabulary words, you need permission if you use the vocabulary words in the same order and arrangement as Pimsleur, or if you use Pimsleur's definitions verbatim.