Battle of Qinghai (727) — the same event in Old Book of Tang and New Book of Tang
Old Book of Tang: Wang Junchuo defeated the Tibetans west of Qinghai and seized their supplies, horses and sheep.; New Book of Tang: Wang Junchuo…
What each source says
Wang Junchuo defeated the Tibetans west of Qinghai and seized their supplies, horses and sheep.
辛丑，涼州都督王君㚟破吐蕃於青海之西，虜輜車、馬羊而還。
Location: 舊唐書 卷8 開元15年 1月
Wang Junchuo, Military Governor of Hexi and Longyou, defeated the Tibetans at Qinghai.
河西、隴右節度使王君㚟及吐蕃戰于青海，敗之
Location: 新唐書 卷005 睿宗·玄宗 開元15年1月