Schema: CREATE TABLE table_name_30 (sub_parish__sokn_ VARCHAR, year_built VARCHAR, location_of_the_church VARCHAR)
Question: What is the Sub-Parish (Sokn) that was built in 1957 in the location of Stavang?
SQL: SELECT sub_parish__sokn_ FROM table_name_30 WHERE year_built = "1957" AND location_of_the_church = "stavang"