DIFF Subgroup
A01G 31/023 Full Title
Soilless cultivation, e.g. hydroponics (growth substrates therefor A01G24/00; cultivation of seaweed A01G33/00) > Special apparatus therefor (self-acting watering devices A01G27/00)
Of 3 combined children, 0 exist in both systems.
3 codes are CPC-only extensions.