SB 8.14.11
etat kalpa-vikalpasya
pramanam parikirtitam
yatra manvantarany ahus
caturdasa puravidah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In one kalpa, or one day of Brahma, there take place the many changes called vikalpas. O King, all of these have been previously described to you by me. Learned scholars who know the past, present and future have ascertained that in one day of Brahma there are fourteen Manus.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Thus end the Bhaktivedanta purports of the Eighth Canto, Fourteenth Chapter, of the Srimad-Bhagavatam, entitled “The System of Universal Management.”