Devibhagavatapurana 7.10.58

7.10.58

kasmāccinmuniputrāttu prāpya mantramanuttamam |
dhyāyanbhagavatīṃ devīṃ prakṛtiṃ paramāṃ śivām ||

But he got from a Muni's son the excellent Mantram of the Highest auspicious Devî Bhagavatî and became merged in the contemplation of that.
Here ends the Tenth Chapter of the Seventh Book on the story of Satyavrata in the Mahâpurânam S'rî Mad Devî Bhâgavatam of 18,000 verses, by Maharsi Veda Vyâsa.

7.10.58.c1

iti śrīmaddevībhāgavate mahāpurāṇe'ṣṭādaśasāhasryāṃ saṃhitāyāṃ saptamaskandhe satyavratākhyānavarṇanaṃ nāma daśamo'dhyāyaḥ ||