بُلُوغُ الْمَرَامِ
Bulugh al-Maram 421
The Book of Prayer
وَلَهُ عَنْ طَلْق ٍ [1] { لَا صَلَاةَ لِمُنْفَرِدٍ خَلْفَ اَلصَّفِّ } [2] .
Ibn Hibban reported this from Talq [bin 'Ali (RA)]: "The prayer of a person who prays alone behind the row is not accepted.
Sunnah.com reference: Book 2, Hadith 327