Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
sach ty » sach tu, sach thu, xach tay
hieu va » lieu va, hieu qua
va hanh » va thanh, va danh, ban hanh
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho
vi su » va su, ve su, ki su

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 ty) or (sach y)) nang x hoi. hieu va cam xuc ((va hanh) or (van hanh)) vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach y)) nang x hoi. hieu va cam xuc ((va hanh) OR (van hanh)) vi su triet.
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach y)) nang x hoi. hieu va cam xuc ((va hanh) or (van hanh)) vi su triet*.