Search "Grace Sward" alone. If she exists, her publications will appear. Then check for GDP or E239 within those papers.

If this is a request for a musical "piece" or session preparation:

Nevertheless, by deconstructing each component, we have identified viable pathways: exploring the work of a potential researcher named Grace Sward, investigating GRACE satellite data for grassland (sward) economic valuation, or checking error codes and database filters.