@book{Polanyietal, author = {Polanyi, Karl and et al.,}, title = {Trade and market in the early empires, Glencoe (The Free Press) 1957.}, language = {en} } @book{Polanyi, author = {Polanyi, Karl}, title = {The great transformation, Beacon Hill (Beacon Press) 1957.}, language = {en} }