Perhaps you should try some spelling variations:
chon loc » cho hoc
dinh dai » dinh dat, sinh dai, dinh dao
sach ky » sach y, sach ty, sach kem
hieu va » lieu va, hieu qua
va chon » va chong, va con, va chan
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
loc va » hoc va, luc va
cua su » qua su
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 (sac ky)) nang x hoi. hieu va chon loc va dinh dai ((cua tre) or (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang x hoi. hieu va chon loc va dinh dai ((cua tre) OR (cua su)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang x hoi. hieu va chon loc va dinh dai ((cua tre) or (cua su))*.