Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
ty hang » ly hang, ty xang, thi hang
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
va doan » va doanh, van doan, va dan
doan vi » doan va, don vi, doan thi
cua tre » cua te, cuu tre, dua tren
hang x » nang x, hoang xa, chang xu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ty hang x hoi. hieu ve ((tac tu) or (cac du)) va doan vi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty hang x hoi. hieu ve ((tac tu) OR (cac du)) va doan vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty hang x hoi. hieu ve ((tac tu) or (cac du)) va doan vi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: thu sach ty hang x hoi. hieu ve ((tac tu) or (cac du)) va doan vi ((cua tre) OR (cua triet))*.