3 ms·Interesting. Buying the 3 books in kindle and may read it on the plane. Wonder what Env needed.by ngcc_hk 8y agoInteresting. Buying the 3 books in kindle and may read it on the plane. Wonder what Env needed.ngcc_hk 8y agoSeems all online no offline one.ngcc_hk 8y agoActually you can offline as in detailed in the GitHub