Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
dang mau » dong mau, dang van, dang su
va trinh » van trinh, va tinh, lap trinh
dang nam » dong nam, dan nam, dung nam
cac truc » cau truc, cac tru, cac trung
te sach » toc sach
hieu va » lieu va, hieu qua
vat cua » mat cua, bat cua, dat cua
truc va » thuc va, thuc vat, trung va
hieu ve » hieu van
sach ty » sach y, sach tu, sach thu
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: te sach ty ((dang mau) or (dang nam)) hoi. ((hieu ve) OR (hieu va)) cac truc va trinh vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((dang mau) OR (dang nam)) hoi. ((hieu ve) OR (hieu va)) cac truc va trinh vat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((dang mau) or (dang nam)) hoi. ((hieu ve) OR (hieu va)) cac truc va trinh vat cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((dang mau) or (dang nam)) hoi. ((hieu ve) OR (hieu va)) cac truc va trinh vat cua tre*.