Petrology of the tephrite-phonolite suite and cognate xenoliths of the Fortaleza district (Ceará, Brazil) - Macciotta, Giampaolo; Almeida, Afonso Rodrigues de; Barbieri, Mario; Beccaluva, Luigi; Brotzu, Pietro; Coltorti, Massimo; Conte, Aida; Garbarino, Carlo; Gomes, Celso B.; Morbidelli, Lucio; Ruberti, Excelso; Siena, Franca; et al. (European Journal of Mineralogy, 1990)