@incollection{:/content/books/9789210019408c001, author = "United Nations Department of Economic and Social Affairs", title = "Introduction", booktitle = "National Accounts Statistics: Analysis of Main Aggregates 2021", publisher = "United Nations", year = "2023", pages = "1-5", url = "https://www.un-ilibrary.org/content/books/9789210019408c001" }