/// <summary> Removes a subject from the list of subjects related to this item </summary>
/// <param name="Subject"> Subject to remove </param>
public void Remove_Subject(Subject_Info Subject)
{
if ((subjects != null) && (subjects.Contains(Subject)))
subjects.Remove(Subject);
}
/// <summary> Add an existing subject to this digital resource </summary>
/// <param name="Subject"> Subject to add to this resource </param>
public void Add_Subject(Subject_Info Subject)
{
if (subjects == null)
subjects = new List<Subject_Info>();
subjects.Add(Subject);
}