Perhaps you should try some spelling variations:
thanh hoi » thanh hoai, thanh hoa, thanh hai
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thuc day » thuc dan, thuc vat
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan
hoi cua » hoi chuc
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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