Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thu nang » thi nang, thu hang, thu bang
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, tu cach
nang xa » nang x, lang xa, nang ma
te sach » toc sach
tu can » tu ban, tu cac, thu canh
tu cua » hu cua, vu cua
dan va » doan va, dan ca, ban va
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) OR (te sach)) thu nang xa hoi. hieu va nam ((tu can) or (tu cua)) dan va su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) thu nang xa hoi. hieu va nam ((tu can) OR (tu cua)) dan va su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) thu nang xa hoi. hieu va nam ((tu can) or (tu cua)) dan va su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) thu nang xa hoi. hieu va nam ((tu can) or (tu cua)) dan va su triet*.