Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
sach thu » sach thue, sach thieu, sach tham
lang ha » long ha
sach ty » sach y, sach tu, xach tay
nam xuc » cam xuc, nam xua, nam thuc
va hanh » va thanh, va danh, ban hanh
su tien » su kien, su hien, tu tieng
ha hoi » hoa hoi, ha noi, xa hoi
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: toc ((sach ty) OR (sach thu)) lang ha hoi. hieu van nam xuc ((va hanh) or (van hanh)) ki su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ty) OR (sach thu)) lang ha hoi. hieu van nam xuc ((va hanh) OR (van hanh)) ki su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ty) OR (sach thu)) lang ha hoi. hieu van nam xuc ((va hanh) or (van hanh)) ki su tien".
• Adding a wildcard symbol may retrieve word variants: toc ((sach ty) OR (sach thu)) lang ha hoi. hieu van nam xuc ((va hanh) or (van hanh)) ki su tien*.