Saleem, Usama. Design of HVDC transmission digital relay / [Thesis or Dissertation] Usama Saleem. - Islamabad : COMSATS University Islamabad, 2019. - xiv, 68 pages : ; 29 cm Subjects--Personal Names: Supervisor, Index Terms--Genre/Form: Electrical and Computer Engineering Dewey Class. No.: 621.3 / SAL-D