CREATE TABLE architect (Id VARCHAR); CREATE TABLE mill (type VARCHAR, architect_id VARCHAR)
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'
โรงสีประเภทใดที่สร้างขึ้นโดยสถาปนิกชาวอเมริกันหรือชาวแคนาดา?
What are the distinct types of mills that are built by American or Canadian architects?