Perhaps you should try some spelling variations:
tinh hoc » sinh hoc, tin hoc, hinh hoc
tu sach » thu sach, su sach, te sach
va tinh » may tinh
cau loc » hau loc, cau hoc, cau luc
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
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 ky ((nang xa) or (nang ma)) hoi. ((hieu va) or (lieu va)) cau loc va tinh hoc cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang ma)) hoi. ((hieu va) OR (lieu va)) cau loc va tinh hoc cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (nang ma)) hoi. ((hieu va) or (lieu va)) cau loc va tinh hoc cua tre*.