1967.

1 and 4 February 1968.

15 February 1968.

22 February 1968.

28-30 March 1968.

11 April 1968.

18 April 1968.

2-4 May 1968.

9-11 May 1968.

16-18 May 1968.

23-25 May 1968.

28-30 May 1968.

27 June 1968.

19 and 20 July 1968.

5-7 September 1968.

12-14 September 1968.

17-19 October 1968.

24-26 October 1968.

31 Oct. - 2 Nov. 1968.

14-16 November 1968.

21-24 November 1968.

18-22 December 1968.

26-29 December 1968.

1969.

1970.