Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
thue nang » thien nang, thuat nang, thi nang
kenh phan » benh nhan, benh phau
va thanh » gia thanh, ban thanh, va tinh
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
ke phan » ve phan, ke thang
nang xa » nang x, lang xa, nang ma
su viet » so viet
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: tu sach thue nang xa hoi. hieu ((ke phan) OR (kenh phan)) duc ((ban hanh) or (va thanh)) vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thue nang xa hoi. hieu ((ke phan) OR (kenh phan)) duc ((ban hanh) OR (va thanh)) vi su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thue nang xa hoi. hieu ((ke phan) OR (kenh phan)) duc ((ban hanh) or (va thanh)) vi su viet".
• Adding a wildcard symbol may retrieve word variants: tu sach thue nang xa hoi. hieu ((ke phan) OR (kenh phan)) duc ((ban hanh) or (va thanh)) vi su viet*.