. . . . "main line" . "defensive line" . . . "Mannerheim Line" . . . "1920\u20131924, 1932\u20131939" . . "primary defensive line" . . "Western literature considered" . . . . . "Mannerheim Line" . . . "Mannerheim Defensive Line" . "Mannerheim" . "Finnish defensive line on the Karelian Isthmus" . .