@InProceedings{hristov_etal:2002,
      AUTHOR = {Hristov, H.D. and Kamburov, L.P. and Urumov, J.R.},
      TITLE = {Comparison on Focusing Characteristics of Curvilinear Fresnel Zone Plates},
      YEAR = {2002},
      MONTH = {September},
      BOOKTITLE = {XII Simposium Nacional de la Uni{\~A}³n Cient{\~A}­fica Internacional de Radio (URSI)},
      PAGES = {469-470},
      ADDRESS = {Alcal{\~A}¡ de Henares (Madrid)}
}