Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham luc » cham soc, nhan luc, cham cuu
ve cham » va cham, ve chat, vu cham
dau cua » day cua, cau cua, dan cua
va danh » va dinh, va dan, va hanh
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
ma hoi » mai hoi, xa hoi, ma hoa
luc va » duc va, tuc va, loc va
y tang » ky tang, 6 tang, 7 tang

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