Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
su triet » su tien, ve triet
su sach » so sach, vu sach
su viet » so viet
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
tu can » tu ban, tu cac, thu canh
tu cua » hu cua, vu cua
va nam » van nam, ha nam, va nay
dan va » doan va, dan ca, ban va

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