Tosefta for Ketubot 9:9
הוֹצִיאָה גֵט וְאֵין עִמּוֹ כְתֻבָּה, גּוֹבָה כְתֻבָּתָהּ. כְּתֻבָּה וְאֵין עִמָּהּ גֵּט, הִיא אוֹמֶרֶת אָבַד גִּטִּי וְהוּא אוֹמֵר אָבַד שׁוֹבְרִי, וְכֵן בַּעַל חוֹב שֶׁהוֹצִיא שְׁטָר חוֹב וְאֵין עִמּוֹ פְרוֹזְבּוּל, הֲרֵי אֵלּוּ לֹא יִפָּרֵעוּ. רַבָּן שִׁמְעוֹן בֶּן גַּמְלִיאֵל אוֹמֵר, מִן הַסַּכָּנָה וְאֵילָךְ, אִשָּׁה גוֹבָה כְתֻבָּתָהּ שֶׁלֹּא בְגֵט, וּבַעַל חוֹב גּוֹבֶה שֶׁלֹּא בִפְרוֹזְבּוּל. שְׁנֵי גִטִּין וּשְׁתֵּי כְתֻבּוֹת, גּוֹבָה שְׁתֵּי כְתֻבּוֹת. שְׁתֵּי כְתֻבּוֹת וְגֵט אֶחָד, אוֹ כְתֻבָּה וּשְׁנֵי גִטִּין, אוֹ כְתֻבָּה וְגֵט וּמִיתָה, אֵינָהּ גּוֹבָה אֶלָּא כְתֻבָּה אַחַת, שֶׁהַמְגָרֵשׁ אֶת אִשְׁתּוֹ וְהֶחֱזִירָהּ, עַל מְנָת כְּתֻבָּה הָרִאשׁוֹנָה מַחֲזִירָהּ. קָטָן שֶׁהִשִּׂיאוֹ אָבִיו, כְּתֻבָּתָהּ קַיֶּמֶת, שֶׁעַל מְנָת כֵּן קִיְּמָהּ. גֵּר שֶׁנִּתְגַּיֵּר וְאִשְׁתּוֹ עִמּוֹ, כְּתֻבָּתָהּ קַיֶּמֶת, שֶׁעַל מְנָת כֵּן קִיְּמָהּ:
If she produced a get, but there were no kethubah with it, [in a place where they do not write a kethubah, but rely upon the condition of beth-din], she collects her kethubah. [For the kethubah-condition is (regarded as) an act of beth-din. And (with) every "act of beth-din," it is as if one is holding the deed. And it is only the one manah or the two manah that she collects, but she does not receive the addition unless she produces the kethubah.] (If she produced) a kethubah, but there were no get with it — she saying: I lost my get, and he saying: I lost my receipt; and, likewise, if a creditor produced a deed of indebtedness, but there were no prozbol with it [(Hillel instituted "prozbol" so that the shemitah year not cancel a debt. By the institution of prozbol, one relegates his deeds to beth-din to collect his debt from the debtor whenever he claims it, so that it does not come under the interdict of (Deuteronomy 15:2): "He shall not exact it," the creditor not exacting it at all, but beth-din doing so.], payment is not exacted. [For we suspect that the woman might have collected her kethubah, and that the debt may have been canceled by the sabbatical year.] R. Shimon b. Gamliel says: From the "danger" on [i.e., after the gentiles had decreed against the observance of mitzvoth and the Jews were afraid to keep their gittin, so that they burned them upon receiving them, and, likewise, with their prozbols], a woman collects her kethubah without a get, and a creditor collects his debt without a prozbol. (If she produced) two gittin and two kethuboth, she collects two kethuboth. Two kethuboth and one get, or one kethubah and two gittin, or one kethubah, one get, and (witnesses that he took her back and) he died, she collects only one kethubah. For if one divorces his wife and takes her back, it is within the framework of the first kethubah that he takes her back. If a minor were married off by his father, her kethubah (written when he was a minor) is valid, for it is within this framework that he kept her (as a wife after he came of age). If one became a proselyte together with his wife, her kethubah (written when they were non-Jews) is valid; for it is within this framework (i.e., that it apply after they became proselytes) that he kept her.