Perhaps you should try some spelling variations:
hien hieu » thien hieu, nhien lieu, dien chieu
thu sach » thuat sach, thuoc sach, thu hoach
danh vai » danh sai, doanh van, dang van
hieu hoc » lieu hoc, hieu hoa, tieu hoc
danh va » doanh va, hanh va, anh va
tu sach » su sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
v nang » va nang, vu nang, van nang
nuoc » quoc, duoc, ngoc

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)) v nang xa hoi. hien hieu hoc nuoc va ((danh vai) or (danh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) v nang xa hoi. hien hieu hoc nuoc va ((danh vai) OR (danh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) v nang xa hoi. hien hieu hoc nuoc va ((danh vai) or (danh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) v nang xa hoi. hien hieu hoc nuoc va ((danh vai) or (danh va)) cua tre*.