What is the real anti-counterfeiting mark in New Concept English?

Both of them are genuine, and the new concept printed earlier is to use the anti-counterfeiting logo of sailboats. Now all the original books sold in bookstores are new (no sailing) signs. The paper quality of the new concept printed by publishing houses and different books will be different. The authenticity of this book depends on the quality of paper and printing. . These two books should only be printed at different times.