@inbook{6057e71dfae44f3f955c0c047315e00f,
title = "Accumulation based on symbolic versus intrinsic {"}productivity{"}: Conceptualizing unequal exchange from Spondylus shells to fossil fuels",
author = "Alf Hornborg",
year = "2000",
language = "English",
isbn = "0-415-23276-7",
pages = "235--252",
editor = "Denemark, {Robert A.} and Jonathan Friedman and Gills, {Barry K.} and George Modelski",
booktitle = "World System History: The Social Science of Long-Term Change",
publisher = "Routledge",
address = "United Kingdom",
}