Shipments to the United States
Due to changes in U.S. customs regulations, all shipments to the United States are now subject to customs clearance.
This means that the recipient will be required to pay customs duties, as well as any applicable taxes and fees upon import.
Please also note that delivery may be delayed while the shipment is being processed by U.S. customs.
![Cover for Paul Keys · Operational Research and Systems: The Systemic Nature of Operational Research - Contemporary Systems Thinking (Paperback Book) [Softcover reprint of the original 1st ed. 1991 edition] (2013)](https://imusic.b-cdn.net/images/item/original/694/9781489906694.jpg?paul-keys-2013-operational-research-and-systems-the-systemic-nature-of-operational-research-contemporary-systems-thinking-paperback-book&class=scaled&v=1395999357)
![Cover for Paul Keys · Operational Research and Systems: The Systemic Nature of Operational Research - Contemporary Systems Thinking (Hardcover Book) [1991 edition] (1991)](https://imusic.b-cdn.net/images/item/original/420/9780306436420.jpg?paul-keys-1991-operational-research-and-systems-the-systemic-nature-of-operational-research-contemporary-systems-thinking-hardcover-book&class=scaled&v=1604016556)