Kishan Gupta, Dharmarajsinh Kosamia, and Dhruval Gadhvi. “Cost Effective & Highly Efficient Method to Producer Qualitative Producer Gas”. International Journal of Advance Research in Engineering, Science & Technology, vol. 4, no. 3, Mar. 2017, pp. 303-7, https://ijarest.org/index.php/ijarest/article/view/914.