All items guaranteed as described, and subject to prior sale. Payment is expected in advance by all but institutional buyers unless arrangements are made in advance. All orders are shipped via the United States Post Office or FedEx unless otherwise requested. New York residents must add 4% sales tax unless a resale or tax exemption certificate is sent. We accept wire transfers, checks and money orders drawn on U.S. banks in U.S. dollars. We also accept Paypal and American Express, Mastercard, VISA and Discover cards (Paypal id firstname.lastname@example.org). Our Guarantee: All purchases are returnable within 30 days IF NOT AS DESCRIBED, presuming they are received in the same condition as sent. Orders usually ship within 2 business days. Shipping costs are based on books weighing 2.2 LB, or 1 KG. However, larger or heavier books or multi-volume sets may require additional postage. We will contact you if additional postage is required.