1. FAO, FAOSTAT, 2015. http://faostat3.fao.org/home/index.html. Accessed date: 11/14/2015.
2. USDA, Trends and developments in hog manure management: 1998-2009, Economic Research Service. 2011. http://www.ers.usda.gov/publications/eib-economic-information-bulletin/eib81.aspx. Accessed date: 07/12/2013.
3. Statistics Korea. 2015. http://www.index.go.kr/egams/stts/jsp/potal/stts/PO_STTS_IdxMain.jsp?idx_cd=1009. Accessed date: 11/14/2015.
4. Characterization of humic substances derived from swine manure-based compost and correlation of their characteristics with reactivities with heavy metals;Chien;J. Agri. Food Chem.,2007
5. J. Otte, D. Roland-Holst, D. Pfeiffer, R. Soares-Magalhaes, J. Rushton, J. Graham, E. Silbergeld, Industrial livestock production and global health risks, PPLPI Research Report. 2007. http://www.fao.org/ag/againfo/programmes/en/pplpi/docarc/rep-hpai_industrialisationrisks.pdf. Accessed date: 07/12/2013.