Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nang cai » nang cao, nang tai, nang cap
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cai hoi » cau hoi, dai hoi, cai hoa
va cam » va cham, va cac, va cao
ve cam » ve cham, ve cac, ve cai

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