@article{williams_nelson_1996, title={Modifying a soilless root medium with aluminum influences phosphorus retention and chrysanthemum growth}, volume={31}, number={3}, journal={HortScience}, author={Williams, K. A. and Nelson, P. V.}, year={1996}, pages={381} }
 @article{williams_nelson_1992, title={Growth of chrysanthemum at low, relatively steady nutrient levels in a commercial-style substrate}, volume={27}, number={8}, journal={HortScience}, author={Williams, K. A. and Nelson, P. V.}, year={1992}, pages={877} }
 @article{williams_nelson_1992, title={Low, controlled nutrient availability provided by organic waste materials for chrysanthemum}, volume={117}, number={3}, journal={Journal of the American Society for Horticultural Science}, author={Williams, K. A. and Nelson, P. V.}, year={1992}, pages={422} }