@article{compton_nelson_1997, title={Timing is crucial for plug seedling substrate testing}, volume={7}, number={1}, journal={HortTechnology}, author={Compton, A. J. and Nelson, P. V.}, year={1997}, pages={63} }
 @article{compton_nelson_1996, title={Plug seedling soil sampling -- timing is critical}, volume={59}, number={13}, journal={GrowerTalks}, author={Compton, A. and Nelson, P.}, year={1996}, pages={60} }