If you enter just the title in the search box at the library website, you actually find it in a few different formats. We have it in print, and you can also access full-text versions online via the HathiTrust digital library.
So why didn't you find it when you searched before? I'm guessing that you entered abbreviations such as "Comp. Psychol. Monog.". When you search the Web using Google, this sort of thing doesn't tend to matter. But library tools are much more restricted in the way they interpret your keywords. If you type an abbreviation, but that abbreviation appears as a whole word in the book or article record, you usually won't find the item.
So when you know what you're looking for, usually the best strategy is to start by entering a few words from the title and the author's last name.