21
22
23
24
25
26
27
28
29
by Plakans, Andrejs
Published 2021
Published 2021
Book
30
31
by Berend, Ivan T.
Published 1998
Published 1998
Book
32
33
by Blumenwitz, Dieter
Published 1989
Published 1989
Book
34
35
36
37
by Enstad, Johannes Due
Published 2018
Published 2018
Book
38
39
Published in The Cambridge history of the First World War
(2014)
Book
40