Bulugh al-Maram 121
Narrated Umm Salamah (RAA):
I said, "O Messenger of Allah, I am a woman who keeps her hair closely plaited. Do I have to undo them for Ghusl after sexual intercourse?" In another narration, "and after the end of menses?" He replied (ﷺ), "No, is it enough for you to throw three handfuls of water over your head."
Related by Muslim.
وَعَنْ أُمِّ سَلَمَةَ رَضِيَ اَللَّهُ عَنْهَا قَالَتْ: { قُلْتُ: يَا رَسُولَ اَللَّهِ إِنِّي اِمْرَأَةٌ أَشُدُّ شَعْرَ رَأْسِي, أَفَأَنْقُضُهُ لِغُسْلِ اَلْجَنَابَةِ? وَفِي رِوَايَةٍ: وَالْحَيْضَةِ? فَقَالَ: 
"لَا, إِنَّمَا يَكْفِيكِ أَنْ تَحْثِي عَلَى رَأْسِكِ ثَلَاثَ حَثَيَاتٍ" }  رَوَاهُ مُسْلِم ٌ  1‏ .‏‏1 ‏- صحيح.‏ رواه مسلم (330)‏، وزاد: "ثم تفيضين عليك الماء فتطهرين".‏