CREATE TABLE table_61328 ("Outcome" TEXT, "Date" FLOAT, "Tournament" TEXT, "Surface" TEXT, "Partner" TEXT, "Opponents in the final" TEXT, "Score in the final" TEXT)

which Surface has Opponents in the final of mark edmondson sherwood stewart, and a Tournament of dallas , u.s.?
SELECT "Surface" FROM table_61328 WHERE "Opponents in the final" = 'mark edmondson sherwood stewart' AND "Tournament" = 'dallas , u.s.'
SELECT "Surface" FROM "table_61328" WHERE "Opponents in the final" = 'mark edmondson sherwood stewart' AND "Tournament" = 'dallas , u.s.'