It looks like you're referring to the Vietnamese ebook Cang Bình Tĩnh, Càng Hạnh Phúc (likely a translation or adaptation of a mindfulness or happiness-focused book, possibly related to The More Calm You Are, The Happier You Are or similar titles like Thích Nhất Hạnh’s works).
It looks like you're referring to the Vietnamese ebook Cang Bình Tĩnh, Càng Hạnh Phúc (likely a translation or adaptation of a mindfulness or happiness-focused book, possibly related to The More Calm You Are, The Happier You Are or similar titles like Thích Nhất Hạnh’s works).