BIEL FESTIVAL, Switzerland "Roland GARROS" of CHESS - Trivia

Trivia Question #1: What year was this?

Trivia Question #2: Who are the 3 GM?

Hello everybody!

Here is today's enigma-trivia for you.

For decades the city of Biel, Switzerland, has become every month of July, the international capital of chess. The city has a particularly outstanding organizer, Hans SURI. This great organizer, and his effective team, year after year have spent enormous energy to establish the historical reference for the International Festival of Chess.

Among the many tournaments that took place at BIEL in 1968, there are three that are particularly noteworthy: they are the interzonal tournaments counting towards the World Championship of Chess. Three editions were held at Biel, a record!

Here is a cliché in the journal SWITZERLAND Chess. Can you guess in what year it was published? Sub question - who are the three GM on the podium?

The answer can be found here!