Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
trang va » tran van
hanh di » hanh vi, hanh de, hang di
hieu va » lieu va, hieu qua
su sach » so sach, vu sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
sach 2 » sach y
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: su sach 2 ((nang xa) or (lang xa)) hoi. hieu va cam ((trang va) OR (hang va)) hanh di va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach 2 ((nang xa) OR (lang xa)) hoi. hieu va cam ((trang va) OR (hang va)) hanh di va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach 2 ((nang xa) or (lang xa)) hoi. hieu va cam ((trang va) OR (hang va)) hanh di va triet".
• Adding a wildcard symbol may retrieve word variants: su sach 2 ((nang xa) or (lang xa)) hoi. hieu va cam ((trang va) OR (hang va)) hanh di va triet*.