All items are offered subject to prior sale. We accept payment with Visa, MasterCard, Discover, American Express, wire transfers in US$, personal or business checks if in US$ drawn on a US bank, and PayPal to orders@oakknoll.com. Invoices and shipments are processed and shipped within 5 business days (excluding weekends and holidays.) Orders in the USA are normally shipped using the US Post office. Other services such as UPS, air mail through the US Post Office and FedEx are available upon request. Foreign shipments are sent via USPS International Mail (either USPS First Class International Mail or USPS Priority International Mail, depending on package weight). In the US, please include US $7.50 for first volume and US $1.00 each additional volume. If ordering outside the US, postage is $30.00 for a single volume unless the book is very large. Postage for heavy books and larger quantities is based on weight. Books are returnable within two weeks. Please notify us before returning a book. Thank you.