@book{Fromm, author = {Fromm, Erich}, title = {Tener o ser?, M{\´e}xico (Fondo de Cultura Econ{\´o}mica) 10° ed., 2006.}, number = {reprint / Nachdruck}, language = {es} } @book{Fromm, author = {Fromm, Erich}, title = {Tener o ser?, M{\´e}xico (Fondo de Cultura Econ{\´o}mica) 20° ed., 2009.}, number = {reprint / Nachdruck}, language = {es} } @book{Fromm, author = {Fromm, Erich}, title = {Tener o ser?, M{\´e}xico (Fondo de Cultura Econ{\´o}mica) 1978.}, number = {translation / {\"U}bersetzung}, language = {es} }