I think I know what ccg is asking. In 1990 and 1991, Leningrad mint seemed to have experimented their packaging for overseas, and hence such sets are in "squarish" paper holders. I am not too sure if a 1989 set exist but so far, these are the ones that I know of.
Alternatively, sets released in Soviet Union were released in either the flimpsy clear plastic sheets, like the example that I have shown, or in hard plastic cases.
I believe kuhli has more infomation on this as I definately don't have enough resource to purchase all possible sets!