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