I've just bought the booklet on Wolf-Schach by A. von Wilpert.
The game was indeed invented in 1943, but the booklet was probably published in 1959 (as mentioned by amazon.de - the booklet itself does not give a date of publication). In fact, the booklet mentions two works written by J. Boyer in 1951 and 1954 respectively.
I've just bought the booklet on Wolf-Schach by A. von Wilpert.
The game was indeed invented in 1943, but the booklet was probably published in 1959 (as mentioned by amazon.de - the booklet itself does not give a date of publication). In fact, the booklet mentions two works written by J. Boyer in 1951 and 1954 respectively.