Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
te sach » toc sach
hieu va » lieu va, hieu qua
va cham » va chat, va tham
dau cua » dai cua, cau cua, dan cua
day cua » dai cua
sach 6 » sach y, sach 2
ma hoi » mai hoi, ma hoa, me hoi
luc va » duc 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: te sach 6 tang ((ma hoi) or (xa hoi)). hieu va cham luc va van ((dau cua) OR (day cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach 6 tang ((ma hoi) OR (xa hoi)). hieu va cham luc va van ((dau cua) OR (day cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach 6 tang ((ma hoi) or (xa hoi)). hieu va cham luc va van ((dau cua) OR (day cua)) triet".
• Adding a wildcard symbol may retrieve word variants: te sach 6 tang ((ma hoi) or (xa hoi)). hieu va cham luc va van ((dau cua) OR (day cua)) triet*.