Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
dau tren » dau tien, dat tren, dau tieng
ky sang » ky dang, ky tang, duy sang
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
va hanh » va thanh, va danh, ban hanh
ve cam » ve cham, ve cac, va cam
va dau » va dao

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