Perhaps you should try some spelling variations:
bach tuoc » sach nuoc
sach duoc » sach nuoc, sach dao, sach dung
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
hanh dai » hanh tai, hanh dao, vanh dai
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, dua tren
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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

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