Perhaps you should try some spelling variations:
sach thu » sach thue, sach tham, cach thuc
hieu van » hieu va, thien van, lieu va
tan hanh » tan thanh, tang hanh, toan hanh
hanh lam » thanh lap, hanh kem, hanh va
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
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: tu ((sach thu) OR (sach thieu)) nang xa hoi. hieu van cam duc tan hanh lam ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach thu) OR (sach thieu)) nang xa hoi. hieu van cam duc tan hanh lam ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach thu) OR (sach thieu)) nang xa hoi. hieu van cam duc tan hanh lam ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach thu) OR (sach thieu)) nang xa hoi. hieu van cam duc tan hanh lam ((cua tre) or (cua te))*.