Carter, J. C. Illinois trees: selection, planting, and care. Illinois 

 Natural History Survey Circular 51. Urbana, Illinois. 1966. 



Crockett, J. U. The Time-Life Encyclopedia of Gardening. 12 volumes. 

 Time-Life Books, Chicago, Illinois. 1972. [See particu- 

 larly the volumes on "Trees", "Flowering Shrubs", and "Lawns 

 and Ground Covers."] 



Dirr, M. A. Manual of woody landscape plants. Their identification, 

 ornamental characteristics, culture, propagation, and uses. 

 Revised edition. Stipes Publishing Company, Champaign, 

 Illinois. 1977. 



Pirone, P. P. Tree maintenance. Fourth edition. 

 Press, New York. 1972. 



Oxford University 



Wyman, D. V/yman's gardening encyclopedia. MacHillan Publishing Comp- 

 any, New York. 1971. [Contains much basic horticultural 

 information. ] 



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