Perhaps you should try some spelling variations:
trinh doc » trinh do, trinh hoa, trinh co
hieu van » hieu va, thien van, hieu ve
va trinh » van trinh, va tinh, lap trinh
doc cua » hoc cua, doi cua, do cua
cau loc » hau loc, cau hoc, cau luc
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
loc va » hoc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((nang xa) or (nang ma)) hoi. ((hieu van) or (lieu va)) cau loc va trinh doc cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang ma)) hoi. ((hieu van) OR (lieu va)) cau loc va trinh doc cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang ma)) hoi. ((hieu van) or (lieu va)) cau loc va trinh doc cua tre*.