Nummenmaa, Tapio Development of sequential structures in chilhood - Helsinski : Suomalainen Tiedeakatemia, 1979. - 56 p. : gráfs ; 24 cm. - Annales Academiae Scientiarum Fennicae ; v. 205 . Bibliografía, p. 55-56 ISBN: 9514103572 Subjects--Topical Terms: NIÑOS-PSICOLOGIA Universal Decimal Class. No.: 159.922.7