Niederhofer H , Staffen W , Mair A (2003) A placebo-controlled study of lofexidine in the treatment of children with tic disorders and attention deficit hyperactivity disorder . J Psychopharmacol17: 113–119
2.
Scahill L , Chappell P B , Kim Y S , Schultz R T , Katsovich L , Shepherd E , Arnsten A F T , Cohen D J , Leckman J F (2001) A placebo-controlled study of guanfacine in the treatment of children with tic disorders and attention deficit hyperactivity disorder . Am J Psychiatry158: 1067–1074
