 Complete the following phrase:  He performed his military service, the following year, in the region of El Kef in north-eastern Tunisia and in Kébili southern Tunisia. He continued to specialize in thoracic and cardiovascular surgery at the Saint-Joseph Hospital of Paris. He got assigned to the general surgery unit of doctors and Zouhair Essafi at the Habib-Thameur Hospital in Tunis. In 1961, over the month of July, he worked as a surgeon in the 