Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
quan cau » quang cao, toan cau, quan ha
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
tay hoi » tay ho, tao hoi, tay thai
xay hoi » xa hoi, cay phoi, gay thoi
ky dang » ky nang, ky danh
qua cau » qua cac, qua ca, qua cai
va cau » van cau, va cac, va dau

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 ky dang ((xay hoi) OR (tay hoi)). hieu ((qua cau) or (quan cau)) truc va hanh va cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky dang ((xay hoi) OR (tay hoi)). hieu ((qua cau) OR (quan cau)) truc va hanh va cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky dang ((xay hoi) OR (tay hoi)). hieu ((qua cau) or (quan cau)) truc va hanh va cau tren".
• Adding a wildcard symbol may retrieve word variants: su sach ky dang ((xay hoi) OR (tay hoi)). hieu ((qua cau) or (quan cau)) truc va hanh va cau tren*.