śreyobhir vividhaiś cānyaiḥ
kṛṣṇe bhaktir hi sādhyate
Śrīla Viśvanātha Cakravartī explains the processes described here as follows. Dāna: donations given to Lord Viṣṇu and His devotees. Vrata: observing vows such as Ekādaśī. Tapas: renunciation of sense gratification for Kṛṣṇa’s sake. Homa: fire sacrifices dedicated to Viṣṇu. Japa: privately chanting the holy names of the Lord. Svādhyāya: study and recitation of Vedic texts such as the Gopāla-tāpanī Upaniṣad.