Perhaps you should try some spelling variations:
thien van » thi van
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
vat tinh » sat tinh, vat sinh, hoat tinh
nang ha » nang hai, nang han, nang hoa
tinh va » tich va, trinh van, trinh vat
cua tre » cua te, cuu tre, dua tren
van am » van nam, van lam, van dam
thuc » thu

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)) ky nang ha noi. thien van am thuc vat tinh va ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang ha noi. thien van am thuc vat tinh va ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang ha noi. thien van am thuc vat tinh va ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang ha noi. thien van am thuc vat tinh va ((cua tre) or (cua triet))*.