Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nang mai » nang ma, nang tai, lang mai
hieu van » hieu va, thien van, lieu va
tinh dai » trinh dai, tinh da, tinh hai
te sach » toc sach
mai hoi » mai khoi, dai hoi, lai hoi
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, dua tren
y nang » ky nang, ly nang, v nang
luc va » tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang mai hoi. hieu van cam ((luc va) OR (duc va)) tinh dai ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang mai hoi. hieu van cam ((luc va) OR (duc va)) tinh dai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang mai hoi. hieu van cam ((luc va) OR (duc va)) tinh dai ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: te sach y nang mai hoi. hieu van cam ((luc va) OR (duc va)) tinh dai ((cua tre) or (cua triet))*.