Perhaps you should try some spelling variations:
cham truc » cau truc, nham thuc, pham thuc
hanh vai » hanh vi, hanh va, hanh tai
nang dai » nang dau, nang tai, lang dai
cua viet » cua vat, cua dieu, va viet
qua cham » qua hai, qua cac, va cham
so sach » so sanh, bo sach, co sach
ca viet » va viet, co viet, san viet
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
sach vu » sach va, sach tu, sach uu
dai hoi » dai hoc, dai hai, dai moi
vu nang » vuc nang, va nang, vu dang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach vu nang dai hoi. hieu qua cham truc va hanh vai ((((cua viet) or (ca viet))) or (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach vu nang dai hoi. hieu qua cham truc va hanh vai ((((cua viet) OR (ca viet))) OR (hoa viet)).
• Adding a wildcard symbol may retrieve word variants: so sach vu nang dai hoi. hieu qua cham truc va hanh vai ((((cua viet) or (ca viet))) or (hoa viet))*.