Search "Grace Sward" alone. If she exists, her publications will appear. Then check for GDP or E239 within those papers.
If you tell me more about your specific project, I can provide: for the E239 seed blend Maintenance schedules for specific climate zones Cost-benefit analysis for large-scale installations gdp+e239+grace+sward
: It is most commonly found in Provolone cheese to prevent the growth of bacteria and fungi. Historically, it was also used in the preservation of caviar. Search "Grace Sward" alone
Combining “sward” with “GDP” is highly unusual unless the context is — where economic value is assigned to ecosystems (grasslands), or agri-economics (productivity of pastures). or agri-economics (productivity of pastures).