Perhaps you should try some spelling variations:
su triet » su tien, ve triet
su sach » so sach, vu sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
hanh ki » hanh vi, hanh ky, hanh kien
su viet » so viet
y lang » o lang, _ lang, tay lang

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 y lang xa hoi. hieu va cac ((duc va) or (truc va)) hanh ki ((su triet) OR (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y lang xa hoi. hieu va cac ((duc va) OR (truc va)) hanh ki ((su triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y lang xa hoi. hieu va cac ((duc va) or (truc va)) hanh ki ((su triet) OR (su viet))".
• Adding a wildcard symbol may retrieve word variants: su sach y lang xa hoi. hieu va cac ((duc va) or (truc va)) hanh ki ((su triet) OR (su viet))*.