Published in Boletin De La Sociedad De Biologia De Concepcion, in 1983, in volume 54, pages 27-33
Published in Boletin De La Sociedad De Biologia De Concepcion, in 1983, in volume 54, pages 35-41
Published in Boletin de la Sociedad de Biología de Concepción, in 1983, in volume 54, pages 43-70