Mishnah Mikvaos 8:4: A gentile woman who discharges semen from a Jew is impure. A Jewish woman who discharges semen from a gentile is pure. If a woman had intercourse with her husband, [literally: her house] and she descended and immersed but did not clean herself [literally: clean the house], it is as though she did not immerse. If ba'al keri immersed before urinating, when he urinates he becomes impure. Rabbi Yose says: [only] regarding one who was sick or elderly is he impure; but a child or a healthy person is pure.

נָכְרִית שֶׁפָּלְטָה שִׁכְבַת זֶרַע מִיִּשְׂרָאֵל, טְמֵאָה. בַּת יִשְׂרָאֵל שֶׁפָּלְטָה שִׁכְבַת זֶרַע מִנָּכְרִי, טְהוֹרָה. הָאִשָּׁה שֶׁשִּׁמְּשָׁה בֵיתָהּ, וְיָרְדָה וְטָבְלָה, וְלֹא כִבְּדָה אֶת הַבַּיִת, כְּאִלּוּ לֹא טָבְלָה. בַּעַל קֶרִי שֶׁטָּבַל וְלֹא הֵטִיל אֶת הַמַּיִם, כְּשֶׁיָטִיל אֶת הַמַּיִם, טָמֵא. רַבִּי יוֹסֵי אוֹמֵר, בְּחוֹלֶה וּבְזָקֵן, טָמֵא. בְּיֶלֶד וּבְבָרִיא, טָהוֹר:

Mishnah Mikvaos 8:5: If a niddah placed money in her mouth, and descended and immersed, she is pure from her impurity [which she had from before], but she is [again rendered] impure because of her saliva [the saliva on the money, a opposed to that which is in her mouth naturally, renders her impure]. If she put her hair in her mouth, clasped her hands [together], or pursed her lips, it is as though she did not immerse. If one grasps on to a person or vessels while immersing them, they are impure. If one washed his hand with water [before grasping them], they are pure. Rabbi Shimon says: he should loosen [his grip] so the waters can surround them. Hidden areas and crevices [in the body] do not need the waters to surround them.

נִדָּה שֶׁנָּתְנָה מָעוֹת בְּפִיהָ וְיָרְדָה וְטָבְלָה, טְהוֹרָה מִטֻּמְאָתָהּ, אֲבָל טְמֵאָה הִיא עַל גַּב רֻקָּהּ. נָתְנָה שְׂעָרָהּ בְּפִיהָ, קָפְצָה יָדָהּ, קָרְצָה שִׂפְתוֹתֶיהָ, כְּאִלּוּ לֹא טָבְלָה. הָאוֹחֵז בְּאָדָם וּבְכֵלִים וּמַטְבִּילָן, טְמֵאִין. וְאִם הֵדִיחַ אֶת יָדוֹ בַּמַּיִם, טְהוֹרִים. רַבִּי שִׁמְעוֹן אוֹמֵר, יְרַפֶּה, כְּדֵי שֶׁיָּבֹאוּ בָהֶם מָיִם. בֵּית הַסְּתָרִים, בֵּית הַקְּמָטִים, אֵינָן צְרִיכִין שֶׁיָּבֹאוּ בָהֶן מָיִם: