Compounds of the rare earth trifluorometanesulfonates with bis(pentamethylene)urea: Synthesis, characterization and thermal stability - Batista, M. K. S.; Marinho, E. P.; Araujo Melo, Dulce Maria de; Vicentini, Geraldo; Zinner, Lea Barbieri; Zinner, Klaus (Rare Earths' 2001, 2001)