Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tinh voi » trinh voi, tinh doi, binh voi
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
van cau » van dau, van hau, van chat
truc va » thuc va, thuc vat, trung va
va tinh » may tinh
voi cua » hoi cua, doi cua, moi cua
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 ty ((nang xa) or (nang ma)) hoi. hieu van cau truc va tinh voi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (nang ma)) hoi. hieu van cau truc va tinh voi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (nang ma)) hoi. hieu van cau truc va tinh voi cua tre*.