CREATE TABLE bridge (architect_id DECIMAL, id DECIMAL, name TEXT, location TEXT, length_meters DECIMAL, length_feet DECIMAL)
CREATE TABLE architect (id TEXT, name TEXT, nationality TEXT, gender TEXT)
CREATE TABLE mill (architect_id DECIMAL, id DECIMAL, location TEXT, name TEXT, type TEXT, built_year DECIMAL, notes TEXT)

What are the distinct types of mills that are built by American or Canadian architects?
SELECT DISTINCT T1.type FROM mill AS T1 JOIN architect AS t2 ON T1.architect_id = T2.id WHERE T2.nationality = 'American' OR T2.nationality = 'Canadian'
SELECT DISTINCT "T1"."type" FROM "mill" AS "T1" JOIN "architect" AS "t2" ON "T1"."architect_id" = "T2"."id" WHERE "T2"."nationality" = 'American' OR "T2"."nationality" = 'Canadian'