Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
dang xay » dang van, van xay
hanh di » hanh vi, hanh de, hang di
sach ly » sach y, sach lo, sach ty
vu sach » vu bach, su sach, vu khach
lang xa » lang ha, lang van
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
di va » dai va, di vao, doi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ly ((lang xa) OR (dang xay)) hoi. hieu va cam ((duc va) or (thuc vat)) hanh di va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ly ((lang xa) OR (dang xay)) hoi. hieu va cam ((duc va) OR (thuc vat)) hanh di va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ly ((lang xa) OR (dang xay)) hoi. hieu va cam ((duc va) or (thuc vat)) hanh di va triet".
• Adding a wildcard symbol may retrieve word variants: vu sach ly ((lang xa) OR (dang xay)) hoi. hieu va cam ((duc va) or (thuc vat)) hanh di va triet*.