R. Cranendonk, C. Kodde, D. Chipeta, E. Zijlstra, and J. Sluiters, “<i>Cryptosporidium parvum</i> and <i>Isopora belli</i> infections among patients with and without diarrhoea”, E Af Med Jrnl, vol. 80, no. 8, pp. 398–401, May 2004.