Srimad Bhagavatam

References to text SB 12.3.52
SB 12.3.52: Whatever result was obtained in Satya-yuga by meditating on Viṣṇu, in Tretā-yuga by performing sacrifices, and in Dvāpara-yuga by serving the Lord’s lotus feet can be obtained in Kali-yuga simply by chanting the Hare Kṛṣṇa mahā-mantra.

Text №
“ ‘Whatever result was obtained in Satya-yuga by meditating on Viṣṇu, in Tretā-yuga by performing sacrifices and in Dvāpara-yuga by serving the Lord’s lotus feet can also be obtained in Kali-yuga simply by chanting the Hare Kṛṣṇa mahā-mantra.’
Lord Sri Caitanya Mahaprabhu Instructs Sanatana Gosvami in the Science of the Absolute Truth
CC 2.20.345