The Ratirahasya (Sanskrit रतिरहस्य) (translated in English as Secrets of Love, also known as the Koka Shastra) is a medieval Indian sex manual written by Kokkoka, a poet, who is variously described as Koka or Koka Pundit. The exact date of its writing is not known, but it is estimated the text was written in the 11th or 12th century. It is speculated that Ratirahasya was written to please a king by the name Venudutta. Kokkoka describes himself in the book as siddha patiya pandita, i.e. "an ingenious man among learned men". The manual was written in Sanskrit. Source: Wikipedia (en)