Mineral chemistry and its genetic significance of major and accessory minerals from a potassic dyke swarm in the Sapucai Graben central-eastern Paraguay - Comin-Chiaramonti, P.; Cundari, Aldo; Gomes, Celso B.; Piccirillo, Enzo Michele; Bellieni, Giuliano; De Min, Angelo; Censi, Paolo; Orué, Delio; Velázquez Fernandez, Victor (Geochimica Brasiliensis, 1990)