Perhaps you should try some spelling variations:
van nham » van nam, van nhan, van tham
thuc dan » thuc hanh, hoc dan, thuc vat
van nang » van quang, van ban, van dong
hieu van » hieu va, thien van, lieu va
thuc va » thuc vat, thuc day
su sach » so sach, vu sach
v nang » va nang, vu nang, voi nang
vi cua » vai cua, di cua
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (van nang)) x hoi. hieu van nham ((thuc va) OR (thuc dan)) hanh vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) OR (van nang)) x hoi. hieu van nham ((thuc va) or (thuc dan)) hanh vi cua te~".
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) OR (van nang)) x hoi. hieu van nham ((thuc va) or (thuc dan)) hanh vi cua te*.