CREATE TABLE table_6542 ("Year" FLOAT, "Men's singles" TEXT, "Women's singles" TEXT, "Men's doubles" TEXT, "Women's doubles" TEXT, "Mixed doubles" TEXT)

Name the men's singles for christian wagener christian esch
SELECT "Men's singles" FROM table_6542 WHERE "Men's doubles" = 'christian wagener christian esch'
SELECT "Men's singles" FROM "table_6542" WHERE "Men's doubles" = 'christian wagener christian esch'