You can now access the new bilingual version of the teaching material prepared by John Griffiths and based on the principles set out by Juan Bermudo in his Declaración de instrumentos musicales (1555). With original tablature, transcriptions in G for lutenists and vihuelists, and in E for guitarists. http://www.vihuelagriffiths.com/JohnGriffiths/Vihuela_playing.html