Núñez-Pons L, Carbone M, Vázquez J, Rodríguez J, Nieto RM, Varela MM, Gavagnin M, Avila C. Natural products from Antarctic colonial ascidians of the genera Aplidium and Synoicum: variability and defensive role. Mar Drugs. 2012 Aug;10(8):1741–64. PMID: 23015772; PMCID: PMC3447337.