Perhaps you should try some spelling variations:
lam truoc » lam thuoc, nam truoc, lam truong
thanh tai » thanh hai, thanh toan, doanh tai
hanh tai » hang tai, han tai, hinh tai
truoc va » truc va, thuoc va, truong va
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
hieu le » hieu ve, hieu he, hieu ly
hieu de » hieu ve, hieu he, lieu de
nang ma » tang ma, sang ma, nang cao
sach 2 » sach y
ma hoi » mai hoi, xa hoi, ma hoa
2 nang » v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach 2 nang ma hoi. ((hieu de) OR (hieu le)) lam truoc va ((hanh tai) or (thanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach 2 nang ma hoi. ((hieu de) OR (hieu le)) lam truoc va ((hanh tai) OR (thanh tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach 2 nang ma hoi. ((hieu de) OR (hieu le)) lam truoc va ((hanh tai) or (thanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach 2 nang ma hoi. ((hieu de) OR (hieu le)) lam truoc va ((hanh tai) or (thanh tai)) cua tre*.