Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
dien va » dien hoa
dien ve » dien he, dien vu, dien viet
va hang » van hang, va nang, va lang
co sach » bo sach, cuon sach, hoc sach
cam thu » nam thu, cac thu, ca thu
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
thu va » thuc va, thue va, tu va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: co sach thi nang xa hoi. ((hieu ve) or (hieu qua)) cam thu va hang ((dien ve) OR (dien va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach thi nang xa hoi. ((hieu ve) OR (hieu qua)) cam thu va hang ((dien ve) OR (dien va)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach thi nang xa hoi. ((hieu ve) or (hieu qua)) cam thu va hang ((dien ve) OR (dien va)) triet".
• Adding a wildcard symbol may retrieve word variants: co sach thi nang xa hoi. ((hieu ve) or (hieu qua)) cam thu va hang ((dien ve) OR (dien va)) triet*.