1. Bremner J.M., Nitrogen-total, in: Sparks D.L., Page A.L., Helmke P.A., Loeppert R.H., Soltanpour P.N., Tabatabai M.A., Johnston C.T., Sumner M.E. (Eds.). (1996). Methods of soil analysis. Part 3-Chemical Methods, Soil Science Society of America, Madison, pp: 1085–1121.
2. Chao, H., & Zhihui, C. (2014). Effects of sludge on growth and physiology of green plant. Pratacultural Science, 31(4), 641–649.
3. Dolgen, D., Necdet, A. M., & Delen, N. (2007). Agricultural recycling of treatment plant sludge: a case study for a vegetable-processing factory. Journal of Environmental Management, 84, 274–281.
4. Hongtao, L. (2015). Heavy metal migration of seepage and runoff triggered by amendment of sludge compost as sod substrate. Environmental Science and Management, 40(10), 92–96.
5. Hu, Y., Pengfei, Z., Jianping, L., & Dezhen, C. (2015). Stabilization and separation of heavy metals in incineration fly ash during the hydrothermal treatment process. Journal of Hazardous Materials, 299, 149–157.