1. Kitterman, L. Tower internals and accessories; Congresso Brasileiro de Petroquimica: Rio de Janeiro, 1976; pp 8–12.
2. Mahiout, S.; Vogelpohl, A. In Mass-Transfer Of Highly Viscous Media On Sieve Trays, Fett Wissenschaft Technologie-Fat Science Technology; Konradin Industrieverlag Gmbh Ernst-Mey-Str 8, 70771: Leinfelden-Echterdingen, Germany, 1987; pp 431–431.