Gordon Royle of the University of Western Australia has collected more than 38,000 examples that fit this criterion and cannot be translated into one another by performing elementary operations.

• 西澳大学的罗艾尔（GordonRoyle）已经蒐集了38000多个满足这个条件的例子，这些例子是已经化约过，不能靠换行或换列来相互转换的。