Perhaps you should try some spelling variations:
duoc tren » nuoc tren, thuoc tren, dung tren
tai duoc » tao duoc, tan duoc, mai duoc
thu sach » thuat sach, thuoc sach, thu hoach
hanh tai » thanh tai, hang tai, han tai
dang cau » hang cau, bang cau, dang mau
tu sach » su sach, te sach, tu cach
ty dang » ty xang, ky dang, ty hang
hieu ve » hieu va, hieu van
xuc va » duc va, tuc va, luc va
loc va » hoc va, luc va
ve cac » va cac, vien cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ty dang cau hoi. hieu ve cac ((xuc va) or (loc va)) hanh tai duoc tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty dang cau hoi. hieu ve cac ((xuc va) OR (loc va)) hanh tai duoc tren.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty dang cau hoi. hieu ve cac ((xuc va) or (loc va)) hanh tai duoc tren*.