Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cham loc » cham soc, chon loc, cham o
cua tre » cua te, cuu tre, dua tren
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, tu cach
tang ma » mang may, tang van
te sach » toc sach
va cham » va chat, va tham
ma hoi » mai hoi, xa hoi, ma hoa
loc va » hoc va, luc 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: ((tu sach) or (te sach)) y tang ma hoi. hieu va cham loc va hanh va ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y tang ma hoi. hieu va cham loc va hanh va ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) y tang ma hoi. hieu va cham loc va hanh va ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) y tang ma hoi. hieu va cham loc va hanh va ((cua tre) OR (cua triet))*.