Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
hanh lam » thanh lap, hanh kem, hanh va
hieu van » hieu va, thien van, lieu va
cau luc » cau truc, cau phuc
cua tre » cua te, cuu tre, dua tren
va hanh » van hanh, va thanh, va danh
nang ma » tang ma, sang ma, nang cao
van cau » van dau, van hau, van chat
luc va » duc va, tuc va, loc va
ma hoi » mai hoi, xa hoi, ma hoa
y nang » ky nang, ly nang, v nang

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) or (toc sach)) y nang ma hoi. hieu van cau luc va hanh lam ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y nang ma hoi. hieu van cau luc va hanh lam ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) y nang ma hoi. hieu van cau luc va hanh lam ((cua tre) or (cua triet))*.