IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, vol. 45, no. 8, page. 1252 - 1255, 1997-08
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, vol. 15, no. 4, page. 256 - 260, 1997-07
THIN SOLID FILMS, vol. 299, no. 1-2, page. 14 - 17, 1997-05-15