Perhaps you should try some spelling variations:
thien van » thi van
nam thuc » nam thuoc, am thuc, nam thu
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
ca tren » cau tren, cu tren, la tren
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
x hoi » xa hoi, o hoi, x ho
di ca » di cau, di cua, doi ca

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: te ((sach ky) OR (sach ty)) nang x hoi. ((lieu va) OR (thien van)) nam thuc va hanh di ca tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sach ty)) nang x hoi. ((lieu va) or (thien van)) nam thuc va hanh di ca tren~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) OR (sach ty)) nang x hoi. ((lieu va) or (thien van)) nam thuc va hanh di ca tren*.