In the November 2016 issue of Chess Life, book reviewer John Hartmann made a very minor mistake in that the title of the Johnsen & Kovacevic book from GAMBIT is - “Win with the London System” (not “Winning…”).
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The GAMBIT ‘Chess Studio’ app (for Android at least) offers this paper book also in dynamic ebook format. The Gambit app ties in nicely with the Analyze This app for instant chess engine access.
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I splurged and purchased both the paper and the ebook of Johnsen’s book. I found that having both formats of the same book available simultaneously during study was significantly better than having only one or the other.
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Both of the London System books that Hartmann reviewed in November 2016 are also available in dynamic ebook format, from ForwardChess.com.