Dowland's Lutes - by Martin Shepherd
Ornamentation in Dowland's Lute Music - by Martin Shepherd
The Solo Lute Music of John Dowland - by David Tayler
Some unobserved information about John Dowland, Thomas Campion and Philip Rosseter By Kenneth Sparr
Singing English Lute Songs - by David Van Ooijen
Useful papers not online:
John M. Ward, The so-called "Dowland lute book" in the Folger Shakespeare Library, JLSA IX, 5-29.
John M. Ward, A Dowland miscellany, JLSA X, 5-153 (updates Poulton's book)