Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cua viet » hoa viet, cua vat, cua dieu
tu sach » thu sach, te sach, tu cach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
cam duc » cam xuc, cao duc, pham duc
van cam » van nam, van lam, van cau
ca viet » va viet, co viet, hoa viet
su sach » so sach, vu sach
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: ((tu sach) or (su sach)) y nang x hoi. hieu van cam duc va hanh di ((cua viet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) y nang x hoi. hieu van cam duc va hanh di ((cua viet) OR (ca viet)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) y nang x hoi. hieu van cam duc va hanh di ((cua viet) or (ca viet))*.