(17) باب صَلاَةِ اللَّيْلِ وَعَدَدِ رَكَعَاتِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي اللَّيْلِ وَأَنَّ الْوِتْرَ رَكْعَةٌ وَأَنَّ الرَّكْعَةَ صَلاَةٌ صَحِيحَةٌ
A hadith like this has been narrated by 'A'isha by another chain of transmitters.
Reference: Sahih Muslim 743 b
In-book reference: Book 6, Hadith 162
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1617