Evaluation of antiulcer activity of the main phenolic acids found in brazilian green propolis - Barros, Muriel Primon de; Lemos, Marivane; Maistro, Edson Luis; Leite, Mateus Freire; Sousa, João Paulo Barreto; Bastos, Jairo Kenupp; Andrade, Sérgio Faloni de (Journal of Ethnopharmacology, 2008)