Los puntos clave no están disponibles para este artículo en este momento.
Frank K. Shuttleworth, The Physical and Mental Growth of Girls and Boys Age Six to Nineteen in Relation to Age at Maximum Growth, Monographs of the Society for Research in Child Development, Vol. 4, No. 3, The Physical and Mental Growth of Girls and Boys Age Six to Nineteen in Relation to Age at Maximum Growth (1939), pp. i+iii+v-vi+1-291
Frank K. Shuttleworth (Sun,) studied this question.