https://blog.gongquiz.com/2020/10/07/guilford%ec%9d%98-%ec%a7%80%eb%8a%a5%ea%b5%ac%ec%a1%b0structure-of-intellect-soi-3%ec%9a%94%ec%86%8c%ea%b0%80-%ec%9e%84%ec%83%81%ec%8b%ac%eb%a6%ac%ec%82%ac-2%ea%b8%89-2019%eb%85%84-8/