Joep Pohlen's Letter Fountain: On Printing Types, published by Taschen, is an encyclopedic reference to typography, an expanded English translation of Pohlen and Geert Setola's Letterfontein (fourth edition). At 600 pages, it's far more extensive than the slim Typographic Desk Reference, and its comprehensive scope makes it the best general typographic reference work.
However, Letter Fountain lacks TDR's clear organisation and cross-referencing. The alphabetised sub-sections and extensive appendices are hard to navigate quickly; if tabbed pages or a detailed general index were added, the book's material would be easier to access. (For a detailed account of typographic history, see Printing Types by Daniel Updike and 20th-Century Type by Lewis Blackwell; in both cases, the first and second editions are superior to the third.)