Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
va hanh » van hanh, va danh, ban hanh
cu tren » tu tren, dua tren
hieu te » hieu ve, hien te, hieu he
ty nang » ky nang, ty xang, ty hang
te ban » te bao
ban co » ban do, san co
x hoi » xa hoi, o hoi, 5 hoi
vi cu » vi su, vi xu, vi du

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang ((x hoi) OR (x ho)). hieu te ban co ((va hanh) or (va thanh)) vi cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ((x hoi) OR (x ho)). hieu te ban co ((va hanh) OR (va thanh)) vi cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ((x hoi) OR (x ho)). hieu te ban co ((va hanh) or (va thanh)) vi cu tren".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ((x hoi) OR (x ho)). hieu te ban co ((va hanh) or (va thanh)) vi cu tren*.