Questions about the product:

Check out our Frequently Asked Questions. If that doesn't cover it, the best way to get an answer is to post your question in the appropriate Forum. (We are notoriously bad at answering email, but we do have a moderator checking the forums a couple of times a day, except on weekends and holidays.)

Technical problems:

Most technical difficulties with our books are handled with this article: Problems with viewing and printing our books, but if that doesn't resolve it, please post the difficulty in the appropriate Forum.

Suggestions and errors:

If you have suggestions, or if you find any errors, we would be very grateful if you could post these in the Forums.

Financial matters:

If you need a refund or credit, please send the details to This e-mail address is being protected from spambots. You need JavaScript enabled to view it . Don't forget to include your invoice number, or if you don't have that, the name on the invoice so that we can look it up.

Business opportunities and licensing:

Please send an email with your ideas to This e-mail address is being protected from spambots. You need JavaScript enabled to view it .