Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
mai khoi » mai khoa, cac khoi, dai khoa
hanh bat » danh bat, hanh cat, doanh bat
tai khoa » da khoa, noi khoa
cau tren » cu tren, dau tren, ca tren
sach ky » sac ky, sach y, sach ty
mai hoi » dai hoi, lai hoi, mai doi
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
bat cau » bat dau, dat cau, bat can
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, luc va

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 khoi) OR (tai khoa)))). hieu ve cam xuc va hanh bat cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((mai hoi) OR (((mai khoi) OR (tai khoa)))). hieu ve cam xuc va hanh bat cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((mai hoi) or (((mai khoi) OR (tai khoa)))). hieu ve cam xuc va hanh bat cau tren".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((mai hoi) or (((mai khoi) OR (tai khoa)))). hieu ve cam xuc va hanh bat cau tren*.