Chai, Tsan SingHansen, Henry L.2010-01-062010-01-061952-07-15Chai, T.S. and Hansen, H.L., (1952), "Characteristics of Black Spruce Seed from Cones of Different Ages", Minnesota Forestry Notes 2, School of Forestry, University of Minnesota0099-4332https://hdl.handle.net/11299/56236Published as Sci. Jour. Ser. Paper No. 2872 of the Univ. of Minn. Agr. Exp. Sta.en-USforests and forestryMinnesotaresearchReport