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

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