부정적분의 초등함수 표현(Integration in finite terms)

• Integration in Finite Terms: The Liouville Theory
  
  • Toni Kasper
  • Mathematics Magazine, Vol. 53, No. 4 (Sep., 1980), pp. 195-201
• An Invitation to Integration in Finite Terms
  
  • Elena Anne Marchisotto and Gholam-Ali Zakeri
  • The College Mathematics Journal, Vol. 25, No. 4 (Sep., 1994), pp. 295-308