Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
cua tre » cua te, cuu tre, cua triet
dan dai » dat dai, can dai, dan dat
va cham » va chat, va tham
sach ky » sac ky, sach y, sach kem
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau
cua tu » cua tuc, cua su, cua cu
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: tu ((sach ky) or (sach ty)) nang x hoi. hieu va cham luc va dan 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 hoi. hieu va cham luc va dan dai ((cua tre) OR (cua tu)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach ty)) nang x hoi. hieu va cham luc va dan dai ((cua tre) or (cua tu))*.