ISRAEL JOURNAL OF MATHEMATICS, vol. 180, no. 1, page. 93 - 118, 2010-12
MATHEMATICA SCANDINAVICA, vol. 103, no. 1, page. 97 - 110, 2008-05
JOURNAL OF THE AUSTRALIAN MATHEMATICAL SOCIETY SERIES A-PURE MATHEMATICS AND STATISTICS, vol. 70, page. 387 - 400, 2001-06