If you are not sure what printing you have, look at the copyright page. The lowest number in the line of numbers following "Printing number:" is the printing.

Because of mistakes on the part of Oxford University Press, the fourth, fifth, sixth, and seventh printings are identical. Some corrections were made in the eighth printing, but, because of further errors on the part of OUP, it is identical to the ninth and tenth printings.

We learned in early 2016 that all copies of the international edition, which appeared in 2010, are apparently equivalent to the first printing of the book, with no corrections at all. We apologize to readers for the incompetence of OUP.