Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, cham soc, pham duy
va hanh » va thanh, va danh, ban hanh
vu cham » va cham, vu kham, tu cham
tu sach » thu sach, te sach, tu cach
tu nang » tru nang, tu nong, tu nano
su sach » so sach, vu sach
hieu vu » hieu va, hieu ve, hieu su
x hoi » xa hoi, o hoi, x ho
le su » ve su, le vu, ly 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) OR (van hanh)) le 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) OR (van hanh)) le 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) OR (van hanh)) le 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) OR (van hanh)) le su triet*.