| Contracting Parties | Signature | Ratification (Instrument deposited on) |
Entry into force |
| GERMANY | 10.09.1964 | 25.06.1969 | 25.07.1969 |
| BELGIUM | 10.09.1964 | / | / |
| FRANCE | 10.09.1964 | 19.07.1983 | 18.08.1983 |
| GREECE | 10.09.1964 | / | / |
| LUXEMBOURG | 10.09.1964 | 20.10.1965 | 06.04.1966 |
| NETHERLANDS | 10.09.1964 | 21.04.1972 | 21.05.1972 |
| SWITZERLAND | 10.09.1964 | 07.03.1966 | 06.04.1966 |
| TURKEY | 10.09.1964 | 25.07.1967 | 24.08.1967 |
| + SPAIN | 10.09.1964 | 22.11.1976 | 22.12.1976 |
| + accession |