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
van nham » van nam, van nhan, van tham
thuc va » thuc vat, thuc day
hanh va » hang va, hanh vi
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca 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) or (toc sach)) ky nang xa hoi. thien van nham ((thuc va) OR (thuc dan)) hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky nang xa hoi. thien van nham ((thuc va) OR (thuc dan)) hanh va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (toc sach)) ky nang xa hoi. thien van nham ((thuc va) OR (thuc dan)) hanh va cua tre*".