Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
lang tai » lang thai, hang tai, tang tai
thue va » thuc va, thuyet va, thuc vat
sach ty » sach tu, sach thu, xach tay
hieu va » lieu va, hieu qua
hang xa » hoang xa, hang va, hang ca
thu va » thuc va, tu va, thu ha
tai su » tai so, tai tu, lai su
va nam » van nam, ha nam, va nay

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