... SAS Institute Inc., SAS/ETS 9.1.2 User’s Guide, Cary, NC: SAS Institute Inc., 2004 [49] SAS Institute Inc., SAS OnlineDoc 9.1.2, Cary, NC: SAS Institute Inc., 2004 [50] Spurr S.H., Forest Inventory, ... knowledge available in the literature on taper and volume modelling Among the three different types of models for describing the taper and estimating stem volume for pedunculate oak that were analyzed, ... critical look at procedures for validating growth and yield models, in: Amaro A., Reed D., Soares P (Eds.), Modelling forest systems, CAB International, Wallingford, Oxfordshire, UK, 2003, 271–293...