TY - JOUR AU - Shih, P; Liu, S; Li, S TI - Weekend effect in upper gastrointestinal bleeding: a systematic review and meta-analysis JO - PeerJ VL - 6 PY - 2018 DO - 10.7717/peerj.4248 L3 - PubMed-ID: 29340247 SP - e428 N1 - et al. ER -