Perhaps you should try some spelling variations:
khoa hoi » khoan hoi, khoa hoc, khoa doi
van hanh » van thanh, ban hanh, van anh
hanh vai » hanh vi, hanh va, hanh tai
su triet » su viet, su tien, ve triet
te sach » toc sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
hoa hoi » hoa hoc, hoa doi, hoc hoi
hieu he » hieu ve, hiem he, hieu le
thu van » thuc van, thuy van, tu van
he nam » ha nam, nghe nam
vai su » va su, van su, lai su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky lang ((hoa hoi) or (khoa hoi)). hieu he nam thu van hanh vai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky lang ((hoa hoi) OR (khoa hoi)). hieu he nam thu van hanh vai su triet.
• Adding a wildcard symbol may retrieve word variants: te sach ky lang ((hoa hoi) or (khoa hoi)). hieu he nam thu van hanh vai su triet*.