STATISTICAL APPENDIX.Published in:Acta Paediatrica, 1972, v. 61, n. s229, p. 23, doi. 10.1111/j.1651-2227.1972.tb16441.xPublication type:Article
INTRODUCTION.Published in:Acta Paediatrica, 1972, v. 61, n. s229, p. 5, doi. 10.1111/j.1651-2227.1972.tb16440.xPublication type:Article