Weight-bearing bones are more sensitive to physical exercise in boys than in girls during pre- and early puberty: a cross-sectional study - Kriemler, S; Zahner, L; Puder, J J; Braun-Fahrlander, C; Schindler, C; Farpour-Lambert, N J; Kranzlin, M; Rizzoli, R (Osteoporos Int, 2008)