Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
danh sai » dung sai, danh bat, danh dau
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thu sac » thu san, thu xac, thu dac
va danh » va dinh, va dan, va hanh
nam xuc » cam xuc, nam xua, nam thuc
cu tren » tu tren, dua tren
mai hoi » dai hoi, lai hoi, mai doi
ky tang » ky nang, ky dang, kho tang
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 sac) OR (thu sach)) ky tang ((mai hoi) or (mai khoi)). hieu van nam xuc va danh sai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sac) OR (thu sach)) ky tang ((mai hoi) OR (mai khoi)). hieu van nam xuc va danh sai cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sac) OR (thu sach)) ky tang ((mai hoi) or (mai khoi)). hieu van nam xuc va danh sai cu tren".
• Adding a wildcard symbol may retrieve word variants: ((thu sac) OR (thu sach)) ky tang ((mai hoi) or (mai khoi)). hieu van nam xuc va danh sai cu tren*.