Perhaps you should try some spelling variations:
cham luan » pham luan, ham luan, phap luan
van doan » van doanh, van toan, van hoan
doan dai » doan hai, toan dai, doan dau
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
x hoi » o hoi, x ho, 5 hoi

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 ((y nang) OR (v nang)) ((x hoi) or (xa hoi)). hieu ve cham luan van doan dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (v nang)) ((x hoi) OR (xa hoi)). hieu ve cham luan van doan dai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (v nang)) ((x hoi) or (xa hoi)). hieu ve cham luan van doan dai cua tre*".