취업교육전문가 김상엽의 티스토리

https://ko.wikipedia.org/wiki/%EC%98%A4%EB%A6%AC%EC%98%A8%ED%99%80%EB%94%A9%EC%8A%A4

https://ko.wikipedia.org/wiki/%EC%84%B8%EC%A0%95%EA%B7%B8%EB%A3%B9

https://ko.wikipedia.org/wiki/%EC%9D%B4%EC%88%98%EA%B7%B8%EB%A3%B9

https://ko.wikipedia.org/wiki/%EC%95%A0%EA%B2%BD%EA%B7%B8%EB%A3%B9

http://100.daum.net/encyclopedia/view/47XCOMD000807

http://100.daum.net/encyclopedia/view/47XCOMD000361

https://ko.wikipedia.org/wiki/SPC%EA%B7%B8%EB%A3%B9

https://www.sedaily.com/NewsView/1VDY0YNJ03

https://terms.naver.com/entry.nhn?docId=652353&cid=43167&categoryId=43167

http://www.autechgroup.co.kr/information.asp

http://www.welcron.com/html/about01.asp

http://news.hankyung.com/article/2018121212321

http://100.daum.net/encyclopedia/view/47XCOMD000433

http://news.mk.co.kr/v2/economy/view.php?year=2018&no=197779

http://news.mk.co.kr/newsRead.php?year=2019&no=10991 https://ko.wikipedia.org/wiki/%EC%9C%A0%EC%A7%84%EA%B7%B8%EB%A3%B9