Perhaps you should try some spelling variations:
hac thuc » hoc thuc, ha thuc, thach thuc
va trien » va truyen, va tuyen, va tieng
danh hai » dang hai, lanh hai, manh hai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
van hac » van hoc, van ha, van hai
sach tu » sach thu, cach tu, sach ty
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
thiet » thieu

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 tu ((nang xa) OR (lang xa)) hoi. hieu van hac thuc va danh hai ((va trien) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu ((nang xa) OR (lang xa)) hoi. hieu van hac thuc va danh hai ((va trien) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu ((nang xa) OR (lang xa)) hoi. hieu van hac thuc va danh hai ((va trien) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: tu sach tu ((nang xa) OR (lang xa)) hoi. hieu van hac thuc va danh hai ((va trien) or (va thiet))*.