Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
mai khoi » mai khoa, tai khoa, cac khoi
dinh vai » dinh van, dinh vi, dinh va
dau tren » dau tien, dat tren, dau tieng
ve chat » va chat, van chat
mai hoi » dai hoi, lai hoi, mai doi
vai dau » va dau, van dau, xvii dau
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
luc va » tuc va, loc va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach y nang ((mai hoi) or (mai khoi)). hieu ve chat ((luc va) OR (duc va)) dinh vai dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y nang ((mai hoi) OR (mai khoi)). hieu ve chat ((luc va) OR (duc va)) dinh vai dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y nang ((mai hoi) or (mai khoi)). hieu ve chat ((luc va) OR (duc va)) dinh vai dau tren".
• Adding a wildcard symbol may retrieve word variants: thuat sach y nang ((mai hoi) or (mai khoi)). hieu ve chat ((luc va) OR (duc va)) dinh vai dau tren*.