1. To this effect, see Spain -Tariff Treatment of Unroasted Coffee L/5135;GATT Panel Report,1989
2. Tariffs are commonly collected either on the basis of an imported good's value (ad valorem), per unit (specific) or a combination of the two (compound);International Economics,2011
3. Agreement on Implementation of Article VII of the General Agreement on Tariffs and Trade 1994 (Customs Valuation Agreement;Article 20 and Annex III