An author's error that makes it through the editing process and published is corrected with "corrigendum sheets". While every effort is made to ensure my books are as accurate as possible, mistakes will happen from time to time. When they are found, the affected sections will be corrected and made available for download here, both in reader-friendly and printer-friendly formats. 

Additionally, sometimes new information relevant to the book's topic may also come up. This will also be made available for download here as an "addendum sheet".