\BOOKMARK [1]{section.1}{Introduction}{} \BOOKMARK [1]{section.2}{Landau theory}{} \BOOKMARK [2]{subsection.2.1}{Restrictions}{section.2} \BOOKMARK [1]{section.3}{Vavilov theory}{} \BOOKMARK [1]{section.4}{Gaussian Theory}{} \BOOKMARK [1]{section.5}{Urb\341n model}{} \BOOKMARK [2]{subsection.5.1}{Fast simulation for n3 16}{section.5} \BOOKMARK [2]{subsection.5.2}{Special sampling for lower part of the spectrum}{section.5}