Reference for Sotah 1:1

הַמְקַנֵּא לְאִשְׁתּוֹ, רַבִּי אֱלִיעֶזֶר אוֹמֵר, מְקַנֵּא לָהּ עַל פִּי שְׁנַיִם, וּמַשְׁקָהּ עַל פִּי עֵד אֶחָד אוֹ עַל פִּי עַצְמוֹ. רַבִּי יְהוֹשֻׁעַ אוֹמֵר, מְקַנֵּא לָהּ עַל פִּי שְׁנַיִם וּמַשְׁקָהּ עַל פִּי שְׁנָיִם:

A man who warns his wife: Rabbi Eliezer says: he warns her [of his suspicions] before two [witnesses], and he makes her drink [the bitter waters] on the testimony of one witness or by his own testimony. Rabbi Yehoshua says: he warns her before two witnesses and makes her drink on the testimony of two [witnesses].

Jastrow

Jastrow