Reference charts for the six-minute walk test in healthy school-aged children from the city of Zaragoza, Spain Ana Villamañán Montero; Carlos Martín de Vicente; Juan Pablo García Íñiguez; Feliciano Ramos Fuentes;

Role of fractional exhaled nitric oxide in patients with sickle cell disease Agustín Muñoz-Cutillas; Sara Bellón-Alonso; Eduardo Bardón-Cancho; Santiago Rodríguez-Tubío-Dapena; Lucía Díez-Llamazares; Rosa Rodríguez-Fernández; Juan Luis Rodríguez-Cimadevilla;

Neuroendocrine cell hyperplasia of infancy: Description of 6 cases Laura Gil Blanco; Alicia Hernando Larroy; Javier Sainz García; Carlos Martín de Vicente;