Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
toc sach » hoc sach, doc sach, thuoc sach
va trinh » van trinh, va tinh, lap trinh
dang mau » dong mau, dang van, dang su
dang nam » dong nam, dan nam, dung nam
vat cua » mat cua, bat cua, dat cua
cac tuc » cac toc, cac tu, cac tac
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
tuc va » thuc va, truc va, tuc xa

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)) ty ((dang mau) or (dang nam)) hoi. hieu ve cac tuc va trinh vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty ((dang mau) OR (dang nam)) hoi. hieu ve cac tuc va trinh vat cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty ((dang mau) or (dang nam)) hoi. hieu ve cac tuc va trinh vat cua tre*.