Articles and other publications by David Lasocki and Batty Bang Mather, including valuable workbooks on cadenza writing, French baroque ornamentation, free ornamentation and preluding.:

From the website of Australian flute maker Terry McGee, an excellent summary of 18th C flute techniques excerpted from the treatises of Rockstro and Nicholson.

An interesting new book by Rogier de Pijper on extended techniques for flute, with exercises that are accessible by younger students:

Book Flute Colors