Flip books are not always separate books, they appear as an added feature in ordinary books or magazines, often in the page corners.
flˈɪp bˈʊks ɑːɹ nˌɑːt ˈɔːlweɪz sˈɛpɹət bˈʊks, ðeɪ ɐpˈɪɹ æz ɐn ˈædᵻd fˈiːtʃɚɹ ɪn ˈɔːɹdɪnˌɛɹi bˈʊks ɔːɹ mˌæɡɐzˈiːnz, ˈɔfən ɪnðə pˈeɪdʒ kˈɔːɹnɚz.