Barthel references the tablets with single capital letters. Tablets H (Large Santiago Tablet) , P (Large Leningrad Tablet), and Q (Small Leningrad Tablet) are the ones that were found to bear the same text with slight variations. In the summer of 1940, during a school visit of the Leningrad (now St Petersburg) Museum, Boris Kudrjavtsev, Valerij Chernuskov and Oleg Klitin became interested in the Easter Island Tablets. They organized themselves into an interest group and, comparing the tablets in the Museum, discovered that two bore basically the same text. Having obtained photographs of tablets held elsewhere, they found more instances of repeated texts. The illustration shows a short excerpt from Tablets H, P, and Q, which is also partly repeated on Tablet A ("Tahua", the "Oar"). The grey cross-hatches represent worn-out, illegible areas. In red, parts common to Tablets H, P and Q, not found on Tablet A. In blue, parts peculiar to Tablet A.