@misc{Polski_Rejestr_Statków_Requirements,
 author={Polski Rejestr Statków},
 howpublished={online},
 publisher={Polski Rejestr Statków},
 language={eng},
 type={e-książka},
 title={Requirements for Baltic Ice Class and Polar Class for ships under PRS supervision, 2019 January},
 keywords={statki, lodołamacze},
}