These subject based dictionaries are quite useful resources. Topical entries contain immediate links to related key concepts. So in this sense, it is lateral: akin to mindmaps. (See the ideas of Tony Buzan.) The below concepts are found in the syllabus document for Cambridge GCE A Level, 9732 H2 Economics (2016). The source is from Nancy Hall. (2001). The complete A-Z Economics Handbook. London. Hodder & Stoughton Educational.
Comparative Advantage: (Note!) Theory (not reality or practice) suggesting that overall output of goods would rise when countries trade. Case assumes only two products (computers and wine); and only two states (Chile and the US). The US is more productive in both goods therefore it holds the absolute advantage. [Implicitly, there is no technological change nor competitors or importing countries.] Applying the theory, both states should specialise in the product for which they are the most efficient. The US in the study focuses on computers while Chile takes on wine. Overall, total production is enlarged. Wall concedes though – ‘It is not possible to say which country will benefit from the increase in output.’ Having more may not mean greater enjoyment it seems. Further, ‘food miles’ for instance would add to pollution due to transport expenditure, not to mention potential food insecurity owing to the dependence on other countries’ supplies.
World Trade Organisation (WTO): It remains the successor to the General Agreement on Tariffs and Trade (GATT) with the majority of world nations as members. At the time of publishing, Wall mentioned that the association largely achieved the paring of tariff trade barriers. In contrast, it had been markedly unsuccessful in paring down agricultural or farming trade restraints.
Arguably, the entries are succinct. Nevertheless, I much prefer one book from the Recommending Reading items found in the earlier syllabus document. It is more comprehensive. Perhaps this because it is also meant for undergraduate usage. See Pass, Christopher; Lowes, Bryan; and Davies, Leslie. (2005). Collins Dictionary: Economics, 2nd Edition. Glasgow. Harper Collins. [I am currently reading the 4th Edition.]