546,069 KEBBON LARS [red.] Scientific studies in mild mental retardation : epidemiology, origin and prevention ; Proceedings of the 2nd European Symposium on scientific studies im mental retardation, Uppsala, Sweden, June 24-26, 1986 / ed. by Karl-Henrik Gustavson ; with Bengt Hagberg, Lars Kebbon, Stephen A. Richardson. — Stockholm ; Uppsala : Almqvist and Wiksell, [1987]. — 240 s. : il., wykr. ; 25 cm (Upsala Journal of Medical Sciences, ISSN 0300-9726 ; suppl. 44)