This is the fourth volume of proceedings of the Āgama seminars convened by the Āgama Research Group at the Dharma Drum Institute of Liberal Arts (formerly Dharma Drum Buddhist College). It comprises nineteen studies, contributed by eighteen different scholars, on various themes related to the Connected Collections of discourses (suttas, sūtras) ― Saṃyutta-nikāya in Pali, Saṃyukta-āgama in Sanskrit ― transmitted by different early Buddhist lineages of reciters, preserved in their Indic originals in Gandhari, Pali and Sanskrit as well as in Chinese and Tibetan translations. This research draws attention to fundamental methodological points posed by the study of these scriptural collections as windows into the formation of early Buddhist texts and the organisation of their transmission.