Get the distinct objects from a list in object

Get the distinct objects from a list in object

I have a class named Member which has object list as a property.
public class Member
{
public string Name { get; set; }
public int Id { get; set; }
public List<Book> BookList { get; set; }
}
public class Book
{
public int Id { get; set; }
public MasterBook master;
}
public class MasterBook
{
public string Author { get; set; }
}
I have a Member object .I want to get the distinct master book objects
from that member object.
Member member = new Member()
{
BookList = new List<Book>()
{
new Book() { Id = 1, master = new MasterBook() { Author =
"Author1" } } ,
new Book() { Id = 1, master = new MasterBook() { Author =
"Author1" } } ,
new Book() { Id = 2, master = new MasterBook() { Author =
"Author2" } } ,
new Book() { Id = 3, master = new MasterBook() { Author =
"Author3" } }
}
};
var distinctIds = member.BookList.Select(book =>
book.master.Author).Distinct();
I am not getting the values for distinctIds. Any idea to complete this