Zoledronic acid for the treatment of osteoporosis in patients with beta-thalassemia: results from a single-center, randomized, placebo-controlled trial - Voskaridou, E; Anagnostopoulos, A; Konstantopoulos, K; Stoupa, E; Spyropoulou, E; Kiamouris, C; Terpos, E (Haematologica, 2006)