Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
trinh ve » trinh he, trinh va, trinh vi
va trinh » van trinh, va tinh, lap trinh
cach hoc » cach thuc, cach thoi, dich hoc
cac loc » cac lop, cac toc, cac hoc
sach ky » sac ky, sach y, sach kem
tang xa » trang xa, tang ma, lang xa
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
ve cua » le cua, de cua, te cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) tang xa hoi. hieu van ((cac loc) OR (cach hoc)) va trinh ve cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach ty)) tang xa hoi. hieu van ((cac loc) or (cach hoc)) va trinh ve cua tre~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sach ty)) tang xa hoi. hieu van ((cac loc) or (cach hoc)) va trinh ve cua tre*.