Ulbrich, M.N.C., and O.H. Leonardos. “The Ultrabasic Potassic Rocks of Presidente Olegario, Serra Da Mata Da Corda, Minas Gerais, Brazil”. International Kimberlite Conference: Extended Abstracts, vol. 5, Feb. 1991, pp. 437-9, doi:10.29173/ikc2596.