first reference to "dualizing object"?

Dear Colleagues, A referee attributed the notion of "dualizing object" in the context of *-autonomous to Grothendieck, but wasn't sure of the exact reference. Does somebody out there happen to know, where this was introduced first? Thank you very much. -- J"urgen Koslowski -- J"urgen Koslowski % If I don't see you no more in this world ITI % I meet you in the next world TU Braunschweig % and don't be late! koslowj@iti.cs.tu-bs.de % Jimi Hendrix (Voodoo Child)