28-29 October 1966.

17-18 February 1967.

4-5 March 1967.

14-15 April 1967.

21-22 April 1967.

5-7 May 1967.

8-11 June 1967.

16-18 June 1967.

13-14 October 1967 (Denver).

13-15 October 1967.

20-21 October 1967 (Denver).

20-22 October 1967.

10-11 November 1967 (Denver).

12-14 January 1968.

26-28 July 1968.