Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
va hanh » van hanh, va thanh, va danh
hieu vu » hieu va, hieu ve, hieu su
tu sach » thu sach, te sach, tu cach
tu nang » tru nang, tu nong, tu nano
su sach » so sach, vu sach
vu cham » va cham, vu kham, tu cham
x hoi » xa hoi, o hoi, x ho
le su » le vu, ly su, de su
ve su » va su

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 (su sach)) tu nang x hoi. hieu vu cham duc va hanh ((le su) OR (ve su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) tu nang x hoi. hieu vu cham duc va hanh ((le su) OR (ve su)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) tu nang x hoi. hieu vu cham duc va hanh ((le su) OR (ve su)) triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) tu nang x hoi. hieu vu cham duc va hanh ((le su) OR (ve su)) triet*.