Perhaps you should try some spelling variations:
vien cac » vien dai, vien da, gian cac
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
nang xa » nang x, lang xa, nang ma
lo van » le van, vo van, so van
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 nang xa hoi. hieu ((vien cac) OR (vien bach)) lo van hanh vai su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang xa hoi. hieu ((vien cac) OR (vien bach)) lo van hanh vai su triet".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang xa hoi. hieu ((vien cac) OR (vien bach)) lo van hanh vai su triet*.