Persson B. NIOH and NIOSH basis for an occupational health standard: chlorocresol / B.Persson, 1990. - 20 p. - Текст : непосредственный.
Stahl E.G. Effect of provenunce and spacing on stem straightness and number of stems with spike knots in pinus sylvestris L. - Northern Sweden and countrywide models / E.G.Stahl,B.Persson,F.Prescher, 1990. - 16 p. - Текст : непосредственный.