"National Symphony Orchestra of Vietnam plans to visit U.S. the resident rat may be gone, but the occasional bat still swoops over the stage at Hanoi's opera house".
Truy cập ngày 28 tháng 2 năm 2015.  ^ “National Symphony Orchestra of Vietnam plans to visit U.S. the resident rat may be gone, but the occasional bat still swoops over the stage at Hanoi’s opera house”.