Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hang hai » hoang hai, hang tai, thanh hai
danh hai » dang hai, lanh hai, manh hai
thuc va » thuc vat, thuc dan, thuc day
co thuc » do thuc, co thua, mo thuc
nano xa » nano va, nano bac, nano cau
tu nano » truc nano
cua tre » cua te, cuu tre, cua triet
va co » vo co

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) tu nano xa hoi. lieu va co thuc va ((danh hai) or (hang hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tu nano xa hoi. lieu va co thuc va ((danh hai) OR (hang hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) tu nano xa hoi. lieu va co thuc va ((danh hai) or (hang hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) tu nano xa hoi. lieu va co thuc va ((danh hai) or (hang hai)) cua tre*.