If you are looking for the Greek version or retailers serving the Greek market, you can find the manga at:
: Volume 23 is especially significant for collectors as it precedes Volume 24, which will contain the late Akira Toriyama's final chapter. Where to Find it (Greek/GR) Watch GR Dragon Ball Super - 23 GR
: This retailer lists Dragon Ball Super Vol. 23 for fans in Greece. If you are looking for the Greek version