5RepoT, Sutinen S, N jd P, et al.Implications of delayed soilthawing on trees : A case study of a Picea abies stand[J].Scandi-navian Journal of Forest Research, 2007 (22) : 118-127.
6RepoT, Lappi J.Estimation of standard error of impedance-estimated frost resistancefj],Scandinavian Journal of Forest Re-search ,1989 ( 4) : 67-74.