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Trees, maps, and theorems (978 90 813 677 07) is published and distributed by Principiae bv. Registered office: Kapellelaan 103, 1950 Kraainem, Belgium (BE 0877 212 174, RPR/RPM Brussels).

We at Principiæ make every effort to ship orders within two business days of receiving the payment on our PayPal or bank account. We are not liable for possible delays introduced in the delivery chain by our shipping partners (postal services or others).

All prices listed on this website (books, shipping, and others) are subject to change without notice. They do not include possible duties on shipments outside the European Union or the United States.

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In accordance with the Belgian legislation, you have the right to notify us that you renounce your purchase within 14 working days after delivery of the goods. If you do, you must return the goods at your expense, in their original state, to the return address indicated on the packing list, in order to receive a full refund.

Address any comment or complaint you may have to Principiae bv, Kapellelaan 103, 1950 Kraainem, Belgium, or simply contact us at . The present terms and conditions will be interpreted and governed in accordance with the laws of Belgium. Any dispute that cannot be settled amicably will be referred solely to the tribunals of Brussels, Belgium.