The reference & criticism index is open. A lot of writing on Tolkien appears first in periodicals or journals, which you will not find here. This site is concerned only with widely marketed books.
There is a vintage audio guide, which includes e-books and and other recordings, in multiple formats.
Other pages, related to collecting in general but not specific to Tolkien collecting (terminology, grading, etc.), are in the info section.
Click Friend and Enter . . . Search The U.S. Tolkien Guide :
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