Coville, Neil, and Alufelwi Tshavhungwe. “Mesoporous Ethanesilica Materials With Bimodal and Trimodal Pore-Size Distributions Synthesised in the Presence of Cobalt Ions”. South African Journal of Science, vol. 106, no. 7/8, July 2010, p. 5 pages, https://sajs.co.za/article/view/10132.