Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
ve cham » va cham, ve chat, vu cham
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
ve cam » ve cac, va cam, ve cai
ma hoi » mai hoi, xa hoi, me hoi
va anh » van anh, va danh, va hanh
anh va » hanh va
va cua » va chua, via cua, ca cua
do va » do van, so va

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 ((ma hoi) or (ma hoa)). hieu ((ve cam) or (ve cham)) do va anh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((ma hoi) OR (ma hoa)). hieu ((ve cam) OR (ve cham)) do va anh va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((ma hoi) or (ma hoa)). hieu ((ve cam) or (ve cham)) do va anh va cua tre*.