Reference for Rosh Hashanah 1:8
אֵלּוּ הֵן הַפְּסוּלִין, הַמְשַׂחֵק בְּקֻבְיָא, וּמַלְוֵי בְרִבִּית, וּמַפְרִיחֵי יוֹנִים, וְסוֹחֲרֵי שְׁבִיעִית, וַעֲבָדִים. זֶה הַכְּלָל, כָּל עֵדוּת שֶׁאֵין הָאִשָּׁה כְשֵׁרָה לָהּ, אַף הֵן אֵינָן כְּשֵׁרִים לָהּ:
These are the ones invalidated (as witnesses by rabbbinic ordinance): those who play with kuvia [bones gambled with in pledge (of imbursement), in violation of the rabbinic dictum that "a surety (asmachta) does not effect acquisition." Those who do so are "robbers" by rabbinic ordinance.], those who lend on interest [They are not "robbers" by Torah law to be invalidated (as witnesses), for it (the interest) is willingly given.], those who race pigeons, [like "kuvia" (above), viz.: "If your pigeon comes in before my pigeon, etc."], those who trade in [produce of] shevi'ith, [of which the Torah writes (Leviticus 25:6): "And it shall be for you to eat" — and not for trade." Because all of these are suspect of readiness to transgress for gain, they are suspected of readiness to testify falsely for a bribe.], and bondsmen [They are invalidated by Torah law, a fortiori from (the instance of) a woman, (who is not kasher to testify).] This is the rule: All testimony that a woman is not kasher for, these, too, are not kasher for. [For there is testimony that a woman is kasher for, e.g., testifying that a woman's husband has died, so that she be permitted to remarry, or testifying that a sotah (a woman suspected of infidelity) was adulterous, so that she not drink (the sotah's draught). And these, who are invalidated by rabbinic ordinance, are also kasher (for such testimony). But those invalidated by Torah law because of transgression were not deemed kasher by the sages for the testimony that a woman may give.]