Perhaps you should try some spelling variations:
thanh hoi » thanh hoai, thanh hoa, thanh hai
ban thanh » ban hanh, ban hang
mai khoi » mai khoa, tai khoa, dai khoa
cac khoi » cac thoi, cac khoan, cach thoi
tu sach » thu sach, su sach, te sach
hoi cuu » hoi chu, hoi cua, ho cuu
dua ban » dia ban, cua ban, qua ban
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach y, sach ty
va cam » va cham, va cac, va cao
ve cam » ve cham, ve cac, ve cai

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 ky nang ((mai khoi) or (cac khoi)). hieu ((ve cam) OR (va cam)) dua ban thanh hoi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((mai khoi) OR (cac khoi)). hieu ((ve cam) OR (va cam)) dua ban thanh hoi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((mai khoi) or (cac khoi)). hieu ((ve cam) OR (va cam)) dua ban thanh hoi cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((mai khoi) or (cac khoi)). hieu ((ve cam) OR (va cam)) dua ban thanh hoi cuu tre*.