Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
va thanh » gia thanh, ban thanh, va tinh
phan duc » pham duc, phan tu, phan dau
sach ty » sach y, sach tu, sach thu
va hanh » van hanh, va danh, ban hanh
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ty hang
hieu ke » hieu kem, chieu ke, hieu ky
ke phan » ve phan, kenh phan, ke thang
x hoi » o hoi, x ho, 5 hoi
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 ty nang ((x hoi) OR (xa hoi)). hieu ke phan duc ((va hanh) or (va thanh)) vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (xa hoi)). hieu ke phan duc ((va hanh) OR (va thanh)) vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((x hoi) OR (xa hoi)). hieu ke phan duc ((va hanh) or (va thanh)) vi su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x hoi) OR (xa hoi)). hieu ke phan duc ((va hanh) or (va thanh)) vi su triet*.