TY - BOOK TI - Antibodies to Helicobacter pylori and pepsinogen levels in children from Costa Rica: comparison of two areas with different risks for stomach cáncer AU - Sierra Ramos, Rafaela PY - 2015 LA - Inglés UR - http://cebp.aacrjournals.org/content/1/6/449.long UR - https://hdl.handle.net/10669/15227 ER -