Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
day trinh » dan trinh, may tinh, lap trinh
cach thuc » anh thuc, cac thu
toc sach » hoc sach, doc sach, thuoc sach
tang van » dang van, hoang van, trong van
thuc day » thuc dan, thuc vat
ve cach » va cach, ve cac, ve canh
vat cua » mat cua, bat cua, dat cua
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
van hoi » van hoa, van hoc, van hoe
ky tang » ky nang, ky dang, kho tang
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: ((su sach) or (toc sach)) ky tang van hoi. hieu ve cach thuc day trinh vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky tang van hoi. hieu ve cach thuc day trinh vat cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (toc sach)) ky tang van hoi. hieu ve cach thuc day trinh vat cua tre*.