Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
danh vai » danh sai, danh va, doanh van
mai khoa » tai khoa, may khoa, dai khoa
ve chat » va chat, van chat
vai cau » va cau, van cau, vai cac
va danh » va dinh, va dan, va hanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
ve cham » va cham, vu cham, ve chim
soc va » hoc va, loc va, doc 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 sang ((mai hoi) or (mai khoa)). hieu ((ve cham) or (ve chat)) soc va danh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang ((mai hoi) OR (mai khoa)). hieu ((ve cham) OR (ve chat)) soc va danh vai cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ((mai hoi) or (mai khoa)). hieu ((ve cham) or (ve chat)) soc va danh vai cau tren*.