Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
mai khoa » tai khoa, may khoa, dai khoa
cham lo » cham o, cam lo, cham soc
tai cua » thai cua, tai cuc, tri cua
va hanh » va thanh, va danh, ban hanh
ve cham » va cham, ve chat, vu cham
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang ((mai hoi) or (mai khoa)). hieu ve cham lo ((va hanh) OR (van hanh)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((mai hoi) OR (mai khoa)). hieu ve cham lo ((va hanh) OR (van hanh)) tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((mai hoi) or (mai khoa)). hieu ve cham lo ((va hanh) OR (van hanh)) tai cua tre*".