Gaya APA

al.], U, M, [. (2015). Productivity of resources and investments at selected ecological farms (7 ( 2015 )). : Elsevier.

Gaya MLA

al.], Urszula, Malaga-Toboła, [et. "Productivity of resources and investments at selected ecological farms". 7 ( 2015 ) : Elsevier, 2015. e-journal.