How many books are in Connie Willis' Doomsday series?
4
3
3
4
3
5
4
3
5
4
3
5
4
3
6
5
4
3
6
5
4
3
6
5
4
3
6
5
4
3
6
5
4
3
6
5
4
3
6
5
4
3
6
5
4
3
6
5
4
7
3
6
5
4
7
3
6
5
4
7
3
6
5
4
7
3
6
5
4
7
3
6
5
4
7
3
6
1
5
4
2
7
6
1
5
4
2
7
6
1
5
2
8
7
6
1
2
8
7
6
1
2
8
7
6
1
2
8
7
0
1
2
8
7
0
1
9
2
8
7
1
9
2
8
7
1
9
2
8
7
1
9
2
8
7
1
9
2
8
7
1
9
2
8
7
1
9
2
8
7
10
1
9
2
8
10
1
9
2
8
10
1
9
2
8
10
11
ten
1
9
2
8
10
11
1
9
2
8
ten
13
10
11
1
9
2
8
13
10
11
9
8
13
10
11
9
8
13
10
11
9
3 volumes