Petkutė, R. (2012). English for sustainable environment: Study book. Technika.
芝加哥风格引文Petkutė, Rūta. English for Sustainable Environment: Study Book. Vilnius: Technika, 2012.
MLA引文Petkutė, Rūta. English for Sustainable Environment: Study Book. Technika, 2012.
警告:这些引文格式不一定是100%准确.