Perhaps you should try some spelling variations:
thien van » thi van
toc sach » hoc sach, doc sach, thuoc sach
thuc dan » thuc hanh, hoc dan, thuc vat
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
thuc va » thuc vat, thuc day
chu tre » cho tre, chu tri, cuu tre
van am » van nam, van lam, van dam
dan va » doan va, dan ca, ban va
va chu » va che, va cau, va chi

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky lang xa hoi. thien van am ((thuc va) or (thuc dan)) dan va chu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. thien van am ((thuc va) OR (thuc dan)) dan va chu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. thien van am ((thuc va) or (thuc dan)) dan va chu tre*.