http://www.citylab.com/commute/2016/05/the-hidden-cost-of-road-fares/482... [4]
http://www.sciencedirect.com/science/article/pii/S0094119016300055 [5]
Links
[1] http://www.si.re.kr/%23
[2] http://facebook.com/sharer.php?u=http%3A%2F%2Fwww.si.re.kr%2Fnode%2F55279&t=%E2%80%9C%EA%B5%90%ED%86%B5%ED%98%BC%EC%9E%A1%EB%B9%84%EC%9A%A9%20%EC%A7%95%EC%88%98%20%EC%8B%A4%EC%A0%9C%20%ED%9A%A8%EA%B3%BC%EB%8A%94%20%EA%B8%B0%EB%8C%80%EC%B9%98%EB%B3%B4%EB%8B%A4%20%EB%82%AE%EC%95%84%E2%80%9D%20%28%EB%AF%B8%EA%B5%AD%29
[3] http://twitter.com/intent/tweet?url=http%3A%2F%2Fwww.si.re.kr%2Fnode%2F55279&text=%E2%80%9C%EA%B5%90%ED%86%B5%ED%98%BC%EC%9E%A1%EB%B9%84%EC%9A%A9%20%EC%A7%95%EC%88%98%20%EC%8B%A4%EC%A0%9C%20%ED%9A%A8%EA%B3%BC%EB%8A%94%20%EA%B8%B0%EB%8C%80%EC%B9%98%EB%B3%B4%EB%8B%A4%20%EB%82%AE%EC%95%84%E2%80%9D%20%28%EB%AF%B8%EA%B5%AD%29
[4] http://www.citylab.com/commute/2016/05/the-hidden-cost-of-road-fares/482943/
[5] http://www.sciencedirect.com/science/article/pii/S0094119016300055
[6] http://www.si.re.kr/world_trends