Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
hieu van » hieu va, thien van, hieu ve
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
lam duc » lam duoc, pham duc, nam duoc
duc van » duc va, duc tan, duc manh
lai cua » hai cua, lai chau, thai cua

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 thu nang xa hoi. ((hieu van) OR (lieu va)) lam duc van hanh ((lai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu nang xa hoi. ((hieu van) OR (lieu va)) lam duc van hanh ((lai cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu nang xa hoi. ((hieu van) OR (lieu va)) lam duc van hanh ((lai cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach thu nang xa hoi. ((hieu van) OR (lieu va)) lam duc van hanh ((lai cua) or (dai cua)) tre*.