Thank you, Professor Barnet, for helping Ray select the new textbook. It's a highly renowned teaching material. However, there appear to be two editions available. The version you previously used was likely the older edition, which explains why the PDF text appears slightly blurred and difficult to read. Would you be able to try the newer edition? Here is the link to the third edition: https://www.kdocs.cn/l/csxhYQvPZD5f