Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
hanh vai » hanh vi, hanh va, hanh tai
vai cuu » vai cua
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
tu sach » thu sach, su sach, te sach
mai hoi » dai hoi, lai hoi, mai doi
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
cuu tre » cua tre, cau tren, cau treo
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: tu sach ((ky lang) OR (ky tang)) ((mai hoi) or (mai khoi)). hieu ve cam xuc va hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky tang)) ((mai hoi) OR (mai khoi)). hieu ve cam xuc va hanh vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) OR (ky tang)) ((mai hoi) or (mai khoi)). hieu ve cam xuc va hanh vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) OR (ky tang)) ((mai hoi) or (mai khoi)). hieu ve cam xuc va hanh vai cuu tre*.