Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
sang mai » sang ma, sang tai, lang mai
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach y, sach ty
xuc van » duc van, luc van, vuc van
ca tren » cau tren, cu tren, la tren
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
ve cau » ke cau, va cau, le cau
ve cac » va cac, vien cac
va cai » va cac, va bai, va dai
vai ca » vai cac, vai cua, bai ca

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 sang mai hoi. hieu ((((va cai) or (ve cau))) or (ve cac)) xuc van hanh vai ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky sang mai hoi. hieu ((((va cai) OR (ve cau))) OR (ve cac)) xuc van hanh vai ca tren.
• Adding a wildcard symbol may retrieve word variants: thu sach ky sang mai hoi. hieu ((((va cai) or (ve cau))) or (ve cac)) xuc van hanh vai ca tren*.