Intraseasonal changes of body composition in professional soccer players and differences according to playing positions - Michailidis, Y.; Michailidis, C.; Primpa, E.; Fatouros, I. G.; Margonis, K.; Chatzinikolaou, A.; Douroudos, I.; Draganidis, D.; Methenitis, S. (Serbian Journal of Sports Sciences, 2013)