1967-07

1967-10

1968-02 to 1968-04

1968-05 to 1968-07

1968-07 to 1968-09

1968-09 to 1968-11

1968-11 to 1969-04

1969-04 to 1969-07

1969-07 to 1969-08

1969-08 to 1969-10?

1971-04 to 1971-05

1971-05 to 1971-07

1971-07 to 1971-09

1971-12

1972-07

1972-10 to 1972-11

1972-11 to 1973-05

1973-06?

1973-07

1973-08

1973-10 to 1974-01

1974-04 to 1974-07?

1974-12 to 1975-08?

1976-01? to 1976-04?

1976-07

1976-07 to 1976-09?

1977-07?

1977-10?

1978-01? to 1978-10?