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
mai hoi » dai hoi, lai hoi, mai doi
ve chat » va chat, van chat
vai dau » va dau, van dau, xvii dau
hieu ve » hieu va, hieu van
sach v » sach va, sach y, sach 2
luc va » tuc va, loc va
v nang » va nang, vu nang, van nang

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 v 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 v 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 v nang ((mai hoi) or (mai khoi)). hieu ve chat ((luc va) or (duc va)) dinh vai dau tren*.