Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
thuc va » thuc vat, thuc dan, thuc day
truc va » thuc vat, trung va
su sach » so sach, vu sach
kv nang » ky nang, ki nang, ke nang
van cam » van nam, van lam, van cau
v nang » va nang, vu nang, van nang
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((v nang) or (kv nang)) xa hoi. hieu van cam ((truc va) or (thuc va)) hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (kv nang)) xa hoi. hieu van cam ((truc va) OR (thuc va)) hanh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) or (kv nang)) xa hoi. hieu van cam ((truc va) or (thuc va)) hanh vi cua viet*.