CREATE TABLE table_name_15 (date VARCHAR, result VARCHAR, bulgarian_commander VARCHAR)

What is the date of Gavril Radomir's Bulgarian Victory?
SELECT date FROM table_name_15 WHERE result = "bulgarian victory" AND bulgarian_commander = "gavril radomir"
SELECT "date" FROM "table_name_15" WHERE "bulgarian victory" = "result" AND "bulgarian_commander" = "gavril radomir"