LITERATURE CITED 



Sonderman, David L., and Robert L. Brisbin. 



1978. A quality classification system for young 

 hardwood trees- the first step in predicting future 

 products. USDA For. Serv. Res. Pap. NE-419. 

 7 p. 



Sonderman, David L. 



1979. Guide to the measurement of tree charac- 



teristics important to the quality classification 

 system for young hardwood trees. USDA For. 

 Serv. Gen. Tech. Rep. NE-54. 12 p. 

 Worley, David P., and Martin Dale. 



1960. Recording tree defects in stereo. USDA 

 For. Serv. Cent. States For. Exp. Stn. Tech. 

 Pap. 173. 11 p. 



MANUSCRIPT RECEIVED FOR PUBLICATION 23 MAY 1980 



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