He was the first chief architect of the Paris World Exhibition of 1937 .
Letrosne was the co-designer ( with his son Daniel ) of the zoo in the Bois de Vincennes in Paris in 1934 .
Letrosne was the first co-designer   of the Paris World Exhibition of 1937 .
Letrosne was the co-designer ( with his son Daniel ) of the zoo in the Bois de Vincennes in Paris in 1934 .