Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
toc sach » hoc sach, thuoc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
thuc day » thuc dan, thuc vat
doc sach » hoc sach, nuoc sach, dac sac
nang xa » nang x, lang xa, nang ma
thuc va » thuc vat, thuc dan
doi cua » dai cua, hoi cua, dong cua
cua tre » cua te, cuu tre, cua triet

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) or (doc sach)) ky nang xa hoi. hieu van nam ((thuc va) OR (thuc day)) thanh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky nang xa hoi. hieu van nam ((thuc va) OR (thuc day)) thanh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (doc sach)) ky nang xa hoi. hieu van nam ((thuc va) OR (thuc day)) thanh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky nang xa hoi. hieu van nam ((thuc va) OR (thuc day)) thanh doi cua tre*.