The Invisible Flag (Penguin books) by Peter Bamm
1962. 1962 reprint. 272 pages. Orange and white pictorial paper cover. Pages are lightly tanned and thumbed at the edges, with light foxing. Binding has remained firm. Corners are dogeared in places. Paper cover is lightly rub worn and thumbed with light shelf wear to edges and corners. Light creases to corners and spine. Tanning to spine and edges.