Perhaps you should try some spelling variations:
thien van » thi van
danh sai » dung sai, danh bat, danh dau
thuc dan » thuc hanh, hoc dan, thuc vat
toc sach » hoc sach, doc sach, thuoc sach
van tham » van thanh, van tuan, van chat
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc day
sai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
x hoi » o hoi, x ho, 5 hoi

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: toc sach ky nang ((x hoi) OR (xa hoi)). thien van tham ((thuc va) OR (thuc dan)) danh sai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang ((x hoi) OR (xa hoi)). thien van tham ((thuc va) or (thuc dan)) danh sai cua tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ((x hoi) OR (xa hoi)). thien van tham ((thuc va) or (thuc dan)) danh sai cua tre*.