You will find the GDS codes for Weinhotel Kaisergarten in Alzey here

AMADEUS (1A):
Chain Code: QR
Property Code QMZ004

SABRE (AA):
Chain Code: QR
Property Code 225206

GALILEO/APOLLO (UA):
Chain Code: QR
Property Code A6854

WORLDSPAN (1P)
Chain Code: QR
Property Code QMZ03

DHISCO (WB)
Chain Code: QR
Property Code 43697