Clausen, Knud E.Kraus, John F.2010-02-082010-02-081961-01-15Clausen, K.E. and Kraus, J.F., (1961), "Air-Layering of Birch", Minnesota Forestry Notes 102, School of Forestry, University of Minnesota0099-4332https://hdl.handle.net/11299/57310Published as Scientific Journal Paper Series No. 4539 of the Minnesota Agricultural Experiment Station.en-USforests and forestryMinnesotaresearchReport