Françoise Sagan (born Françoise Delphine Quoirez; 21 June 1935 – 24 September 2004) was a French playwright, novelist, and screenwriter. Sagan was known for works with strong romantic themes involving wealthy and disillusioned bourgeois characters. Her best-known novel was her first, Bonjour Tristesse (1954), which was written when she was a teenager.
Source : Wikipedia
