Origin of "I am not sure that I exist..." quote

[Brian]

In what book or other publication was this commonly quoted line by Jorge Luis Borges first published? From the way it is described online, it sounds like it must have come from an interview or perhaps he said it in conversation with someone and it eventually found its way into print.

English: "I am not sure that I exist, actually. I am all the writers I have read, all the people I have met, all the women I have loved; all the cities I have visited, all my ancestors."

Spanish: "No estoy seguro de que existo, en realidad yo soy todos los escritores que he leído, todas las personas que he conocido, todas las mujeres que he amado,. Todas las ciudades que tengo visitados, todos mis antepasados.

[Angharad]

Using Wikiquotes, it looks like it's from an interview Borges did with El Pais in 1981.

[Lobstergirl, au gratin]

Moving to "Just to Chat" which is where quote requests go.

[Brian]

Thank you, Angharad! Yes, that looks like it.