Enoxaparin plus compression stockings versus compression stockings alone in the prevention of venous thromboembolism after elective neurosurgery - Agnelli, G; Piovella, F; Buoncristiani, P; Severi, P; Pini, M; D’Angelo, A; Beltrametti, C; Damiani, M; Andrioli, GC; Pugliese, R; Iorio, A; Brambilla, G (N Eng J Med, 1998)