CREATE TABLE table_18415 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB, "Candidates" CLOB)

What district is incumbent elmer j. holland from?
SELECT "District" FROM table_18415 WHERE "Incumbent" = 'Elmer J. Holland'
SELECT "District" FROM "table_18415" WHERE "Incumbent" = 'Elmer J. Holland'