@ARTICLE{Kurpaska_Sławomir_Energy_2012,
 author={Kurpaska, Sławomir and Latała, Hubert and Knaga, Jarosław},
 number={No 1},
 journal={Teka Commission of Motorization and Power Industry in Agriculture},
 howpublished={online},
 year={2012},
 publisher={The Lublin Branch of the Polish Academy of Sciences},
 title={Energy effi ciency analysis of fl at and vacuum solar collector systems},
}