He found that they had similar structures .
Postnikov , Kamaletdinov studied the foundations of ancient and young platforms : Eastern European , Western European , Siberian , West Siberian , North American , and African .
Kamaletdinov found that they had similar structures .
Postnikov , Kamaletdinov studied the foundations of ancient and young platforms : Eastern European , Western European , Siberian , West Siberian , North American , and African .