Analysis of eleven phenolic compounds including novel p-coumaroyl derivatives in lettuce (Lactuca sativa L.) by ultra-high-performance liquid chromatography with photodiode array and mass spectrometry detection - Ribas-Agustí, A; Gratacós-Cubarsí, M; Sárraga, C; García-Regueiro, J A; Castellari, M (Phytochem Anal, 2011)