There were 429 titles published in the White Circle Pocket series by the Canadian publisher Wm. Collins & Sons Co. Canada between 1942 and 1952. Pan Books in England began publishing in 1945 and continues as Pan Macmillan. According to a collector's site there are 2,391 numbered Pans. How many of the 429 White Circles were also published by Pan? We shall see. But here is another one.