Litz Coil References
F.D. Doty, G. Entzminger, C.D. Hauck
"Error-Tolerant RF Litz Coils for NMR/MRI."
J. Magn. Reson. 140:17-31 (1999)

F.D. Doty
"Low Inductance Transverse Litz Foil Coils."
U.S. Patent #6,060,882

F.D. Doty, G. Entzminger, Z. Rafique, L. Holte, T. Welsh
"The Litzcage - a High-field Circular-polarized RF Coil with Improved Tunability, B1 Homogeneity, and S/N."
http://www.dotynmr.com/images/documents/RFLC__000.pdf