This collection of early Rabbinic legal code was compiled by Judah ha-Nasi in the 2nd century. It is divided into 6 parts called orders. Each order (or seder) is subdivided into sections called tractates (or masechet).
The orders are:
Complete sets of the Mishnah are generally shelved in BM 497. They are shelved in this order: original language (BM 497), selections (BM 497.2), translations (BM 497.5), early works about the Mishnah (BM 497.7), then later works (BM 497.8). Individual orders and tractates of the Mishnah are shelved with individual orders and tractates of the Talmud under BM 506 (see below). Note: many of these works are shelved in the oversized (folio) section.
To find texts of the Mishnah do a title browse search for: mishnah <part (order or tractate)> <language>
To find books written about the Mishnah, do a subject browse search under: mishnah <part>
Jewish texts at Snunit
Includes the Hebrew texts of the Tanakh, Mishnah, Tosefta, Talmud Bavli, Talmud Yerushalmi, and Mishneh Torah
Bar Ilan Responsa Project
Includes the Hebrew texts of the Tanakh, Talmuds, early commentaries, and many responsa http://www.responsa.co.il/
More options are available to HUC students and faculty by accessing the Responsa Project through the Jewish Studies Portal
Sayings of the Jewish Fathers (Pirqe Aboth)
Translated by Charles Taylor 
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