Perhaps you should try some spelling variations:
thanh duoc » hanh duoc, tranh duoc, thanh phuoc
hieu van » thien van, lieu va, hieu ve
va thanh » gia thanh, ban thanh, va tinh
thanh ve » hanh ve, thanh va, thanh vien
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
duoc va » nuoc va, duc va, duoc ma
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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