The seriousness of the Mitzvah: Nedarim 31b
Liability for Divine Excommunication, or for an offering, for failing to perform this Mitzvah: Makkot 13b
Source for the father's obligation: Kiddushin 29a
Source for the Court's obligation, if the father fails: Kiddushin 29a
Source for the son's obligation himself, if the father and Court fail: Kiddushin 29a
Whether the mother is obligated to have her son circumcised, or only the father is obligated: Kiddushin 29a [2x]
Linking the Circumcision Requirement to any case where the mother would have to undergo Purification of a Woman who has Given Birth: Shabbat 135a
Dripping a drop if blood for one born circumcised: Shabbat 135a