Gaya APA

leal-arcas, R, ;, R, J, A, ;, G, C. (). The European Union and its energy security challenges . [s.i.]: .

Gaya MLA

leal-arcas, Rafael, ;, Rıos,, Juan, Alemany, ;, Grasso,, Costantino. "The European Union and its energy security challenges". [s.i.]: , . Text.