text: select StudentId
  from Students
  where not exists (
      select StudentId
      from Lecturers, Plan
      where Lecturers.LecturerId = Plan.LecturerId
        and LecturerName = :LecturerName
        and Plan.GroupId = Students.GroupId
        and not exists (
            select Mark
            from Marks
            where Marks.StudentId = Students.StudentId
              and Marks.CourseId = Plan.CourseId
          )
    )
  