In the UNESCO definition. a 'Pamphlet’ is an unbound publication that is not a periodical and contains:
1
No fewer than 5 and no more than 48 pages.
2
No fewer than 10 and no more than 68 pages.
3
No fewer than 15 and no more than 64 pages.
4
No fewer than 20 and no more than 80 pages.