Świątek, M., A. Lewicki, D. Szymanowska, and P. Kubiak. “The Effect of Introduction of Chicken Manure on the Biodiversity and Performance of an Anaerobic Digester”. Electronic Journal of Biotechnology, vol. 37, Jan. 2019, https://preprints.pucv.cl/index.php/ejbiotechnology/article/view/2018.11.002.