Malik narrated to us, and he mentioned the same, and he added: then she becomes lawful.
Yunus bin Yazid narrated it from al-Zuhri, and he added in it that Uthman (may Allah be pleased with him) also gave the same judgement after Umar (may Allah be pleased with him).
And Abu Ubayd narrated it in his book from Muhammad bin Kathir, from al-Awza'i, from al-Zuhri, from Sa'id bin al-Musayyab (may Allah have mercy on him), that Umar and Uthman (may Allah be pleased with them both) said: The wife of the missing husband should wait four years, then observe an 'iddah of four months and ten days, then she may marry.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العدد / 15567