From the back cover of the Penguin Crime Edition The Terrorists written in 1975:
There is a lot information about the couple, and the philosophy behind the 10 books.
I was particularly intrigued by this charming passage:
They married next year  and the carefully planned crime series was created in the evenings, after their two sons, Tetz and Jens, had been put to bed.
Here are the complete series of books with those that I have read starred.
1966 - The Man Who Went Up in Smoke*
1967 - The Man on the Balcony*
1968 - The Laughing Policeman*
1969 - The Fire Engine That Disappeared
1970 - Murder at the Savoy
1971 - The Abominable Man
1972 - The Locked Room*
1974 - Cop Killer*
1975 - The Terrorists*
"I hope more of the King of Sweden's own person than of all his country......he is all and worth all."
Thomas Roe on Gustavus Adolphus quoted in The Thirty Years War;C.V.Wedgewood
By the way anyone who visits Stockholm should not miss the Vasa Museum. The loss of this great warship in 1628 on its maiden voyage was the Titanic disaster of the 17th century.
I think it is time to move on to a warmer climate, perhaps Southern Italy, but I will await the 2007 reprints of Sjowall and Wahloo with great anticipation.