Barta-Juhász, L. I. . “The Statistical Analysis for the Theoretical Bio-Methane Market Based on the Opinion of Car-Owners of Hajdú-Bihar County in Hungary”. Applied Studies in Agribusiness and Commerce, vol. 7, no. 4-5, Dec. 2013, pp. 27-30, doi:10.19041/APSTRACT/2013/4-5/3.