Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
va cham » va chat, va tham
dau dai » dat dai, sau dai, dau da
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
va dau » va dao
cua tu » cua tuc, cua su, cua cu

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 ky) or (sach ty)) nang x ho. hieu va cham luc va dau dai ((cua tre) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang x ho. hieu va cham luc va dau dai ((cua tre) OR (cua tu)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach ty)) nang x ho. hieu va cham luc va dau dai ((cua tre) or (cua tu))*.