, ▁the ▁cost ▁and ▁effect iveness ▁of ▁the ▁Mag in ot ▁system ▁was ▁called ▁into ▁question . ▁Between ▁ 1 9 6 4 ▁and ▁ 1 9 7 1 ▁nearly ▁all ▁of ▁the ▁Mag in ot ▁fort ifications ▁were ▁de activ ated . ▁ ▁See ▁also ▁ ▁List ▁of ▁Al pine ▁Line ▁ouv rages ▁ ▁References ▁ ▁Bibli ography ▁All c orn , ▁William . ▁The ▁Mag in ot ▁Line ▁ 1 9 2 8 - 4 5 . ▁Oxford : ▁O sp rey ▁Publishing , ▁ 2 0 0 3 . ▁ ▁Kauf mann , ▁J . E . ▁and ▁Kauf mann , ▁H . W . ▁Fort ress ▁France : ▁The ▁Mag in ot ▁Line ▁and ▁French ▁Def enses ▁in ▁World ▁War ▁II , ▁Stack pole ▁Books , ▁ 2 0 0 6 . ▁ ▁Kauf mann , ▁J . E ., ▁Kauf mann , ▁H . W ., ▁Jan c ovi č - P oto č nik , ▁A . ▁and ▁Lang , ▁P . ▁The ▁Mag in ot ▁Line : ▁History ▁and ▁Guide , ▁Pen ▁and ▁S word , ▁ 2 0 1 1 . ▁ ▁Mary , ▁Jean - Y ves ; ▁H ohn adel , ▁A lain ; ▁Sic ard , ▁Jacques . ▁H ommes ▁et ▁O uv rages ▁de ▁la ▁L igne ▁Mag in ot , ▁T ome ▁ 1 . ▁Paris , ▁Histoire ▁& ▁Col lections , ▁ 2 0 0 1 . ▁▁ ▁Mary , ▁Jean - Y ves ; ▁H ohn adel ,