참고 1
https://www.prism.go.kr/homepage/entire/downloadResearchAttachFile.do?workKey=001&fileType=CPR&seqNo=001&researchId=1351000-201500395&pdfConvYn=Y
참고 2
https://www.kipf.re.kr/cmm/fms/FileDown.do;jsessionid=C52FE23D56F9BEFBA0F444AA4D909A08?atchFileId=FILE_000000000005653&fileSn=0
참고 3
https://repository.kihasa.re.kr/bitstream/201002/365/1/%EC%97%B0%EA%B5%AC03-12.pdf