Official source · Urban Farm DB

UPOV/EXN/EXC/1 — Explanatory Notes on Exceptions to the Breeder's Right under the 1991 Act of the UPOV Convention

This source is cited by the column “The law came in 1930 and patent number one went to a climbing rose — rights over plant varieties were built in under a century.” This page records the connection before you continue to the external source.