A. E.  Thessen, Stoecker, D. K., Tango, P., Morton, S. L., and Caron, D., ?The presence of domoic acid in Pseudo-nitzschia from the Choptank River, a Chesapeake Bay tributary?, Second Symposium on Harmful Marine Algae in the U. S. Woods Hole, Massachusetts, p. 130, 2003.