TY - JOUR AU - Siersema, Peter D. TI - Foreword SN - 0013-726X SN - 1438-8812 PY - 2021 JO - Endoscopy JF - Endoscopy LA - EN VL - 54 IS - 01 SP - 1 EP - 1 DA - 2021/12/16 PB - Georg Thieme Verlag KG DO - 10.1055/a-1680-9087 UR - http://www.thieme-connect.de/products/ejournals/abstract/10.1055/a-1680-9087 ER -