John C. Poirier, “Purity Beyond the Temple in the Second Temple Era,” Journal of Biblical Literature 122.2 (2003), pp. 247-265.
Yonatan Adler, “Purity in the Roman Period,” The Oxford Encyclopedia of the Bible and Archaeology, vol. 2 (New York: Oxford Univ. Press, 2013), pp. 240-249.
Vered Noam, “Stringency in Qumran: A Reassessment,” Journal for the Study of Judaism 40.3 (2009), pp. 342-355 (345).
See Jürgen Zangeberg, “Pure Stone: Archaeological Evidence for Jewish Purity Practices in Late Second Temple Judaism (Miqwa’ot and Stone Vessels),“ in Christian Frevel and Christophe Nihan, eds., Purity and the Forming of Religious Traditions in the Ancient Mediterranean World, Dynamics in History and Religion, vol. 3 (Leiden: Brill, 2013), pp. 537-572 (553).
Stuart S. Miller, At the Intersection of Texts and Material Finds: Stepped Pools, Stone Vessels, and Ritual Purity Among the Jews of Roman Galilee (Göttingen: Vandenhoeck Ruprecht, 2015), pp. 51-55, 63-103.
On the possible influence of the Greek hip-baths for the development of mikva’ot, see Yonatan Adler, “The Hellenistic Origins of Jewish Ritual Immersion,” Journal of Jewish Studies 69 (2018), pp. 1-21.