Petitcolas, F.A.P.: 'Towards ‘robust' watermarks', IET Conference Proceedings, 2000, p. 1-1, DOI: 10.1049/ic:20000213
IET Digital Library, https://digital-library.theiet.org/;jsessionid=ap015fvtjwlo.x-iet-live-01content/conferences/10.1049/ic_20000213