Eyal, N. (2014). Hooked: How to build habit-forming products. Portfolio/Penguin.
Chicago-viite (17. p.)Eyal, Nir. Hooked: How to Build Habit-forming Products. London: Portfolio/Penguin, 2014.
MLA-viite (9. p.)Eyal, Nir. Hooked: How to Build Habit-forming Products. Portfolio/Penguin, 2014.
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