Perhaps you should try some spelling variations:
thanh dieu » thanh lieu, than dieu, hanh dieu
hieu van » hieu va, thien van, lieu va
tang hoa » hang hoa, tang ha, tang ho
dieu tra » dieu tri, kiem tra, dieu cua
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, te sach, tu cach
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky tang » ky nang, ky dang, kho tang
su sach » so sach, vu sach
tra tre » tran tren, tran tri, tran tro
nam tu » nam thuc

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 (su sach)) ky tang hoa hoi. hieu van ((nam tu) or (nam thu)) va thanh dieu tra tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky tang hoa hoi. hieu van ((nam tu) OR (nam thu)) va thanh dieu tra tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky tang hoa hoi. hieu van ((nam tu) or (nam thu)) va thanh dieu tra tre*.