This page lists the databases with the largest holdings of law reviews and law books in PDF, which you can search directly. Most of the legal books that have been digitized are historic and date back roughly a hundred years or more. The Restatements are available through HeinOnline.
HeinOnline: After selecting the Restatements title you need, scroll down to the bottom, past the drafting documents, to find its final incarnation.
Many law reviews now make their issues available online in PDF. Failing these databases, see if the website of the desired law review has an online archive of articles.