Perhaps you should try some spelling variations:
chat triet » chet triet, phat trien, chat thien
lam chat » luan chat, cao chat, ly chat
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach y, sach ty
va hanh » va thanh, va danh, ban hanh
vien da » vien dai, hien dai
su sach » so sach, vu sach
tang ha » lang ha, tang ma, trung ha
ky tang » ky nang, ky dang, kho tang
ve cac » va cac, vien cac
ha hoi » hoa hoi, ha noi, xa hoi

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 tang ha hoi. hieu ((ve cac) or (vien da)) duc ((va hanh) OR (van hanh)) lam chat triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang ha hoi. hieu ((ve cac) OR (vien da)) duc ((va hanh) OR (van hanh)) lam chat triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky tang ha hoi. hieu ((ve cac) or (vien da)) duc ((va hanh) OR (van hanh)) lam chat triet".
• Adding a wildcard symbol may retrieve word variants: su sach ky tang ha hoi. hieu ((ve cac) or (vien da)) duc ((va hanh) OR (van hanh)) lam chat triet*.