Perhaps you should try some spelling variations:
may thoi » gay thoi, may thi, tay thoi
te sach » toc sach
may hoi » tay hoi, mai hoi, may hmi
hieu ve » hieu va, hieu van
ve nang » va nang, ke nang, de nang
va danh » va dinh, va dan, va hanh
dau cua » dai cua, day cua, cau cua
y mang » cay mang
luc va » duc va, tuc va, loc va
cu cua » cau cua, ca cua, co cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y mang ((may hoi) OR (may thoi)). hieu ve nang luc va danh ((dau cua) OR (cu cua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y mang ((may hoi) OR (may thoi)). hieu ve nang luc va danh ((dau cua) or (cu cua)) triet~".
• Adding a wildcard symbol may retrieve word variants: te sach y mang ((may hoi) OR (may thoi)). hieu ve nang luc va danh ((dau cua) or (cu cua)) triet*.