Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
quan cau » quang cao, toan cau, quan ha
dang xay » dang van, van xay
van hanh » van thanh, ban hanh, van anh
va hanh » va thanh, va danh, ban hanh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
qua cau » qua cac, qua ca, qua cai
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
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. hieu ((qua cau) or (quan cau)) truc ((va hanh) OR (van hanh)) va cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky dang xay hoi. hieu ((qua cau) OR (quan cau)) truc ((va hanh) OR (van hanh)) va cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky dang xay hoi. hieu ((qua cau) or (quan cau)) truc ((va hanh) OR (van hanh)) va cau tren".
• Adding a wildcard symbol may retrieve word variants: su sach ky dang xay hoi. hieu ((qua cau) or (quan cau)) truc ((va hanh) OR (van hanh)) va cau tren*.