Table schema:
CREATE TABLE table_name_83 (representative VARCHAR, title VARCHAR, termination_of_mission VARCHAR)

Question: Which representative was the Ambassador Extraordinary and Plenipotentiary and had a Termination of Mission date September 20, 1996?
SQL: SELECT representative FROM table_name_83 WHERE title = "ambassador extraordinary and plenipotentiary" AND termination_of_mission = "september 20, 1996"