Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cham luc » cham soc, nhan luc, cham cuu
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
luc may » truc may, phuc may
bai cua » ban cua, dai cua, hai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky nang xa hoi. ((hieu ve) or (lieu va)) cham luc may tinh ((bai cua) OR (bai ca)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang xa hoi. ((hieu ve) OR (lieu va)) cham luc may tinh ((bai cua) OR (bai ca)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang xa hoi. ((hieu ve) or (lieu va)) cham luc may tinh ((bai cua) OR (bai ca)) tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang xa hoi. ((hieu ve) or (lieu va)) cham luc may tinh ((bai cua) OR (bai ca)) tre*.