Perhaps you should try some spelling variations:
cham luc » cham soc, cham cuu, chat lua
tinh via » tinh gia, tinh va, tinh vi
sach thu » sach thue, sach thieu, sach tham
nhan luc » nang luc
via cua » gia cua, gian cua, giau cua
sach ly » sach y, sach lo, sach ty
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
va hoi » xa hoi, va hoc, va hoa

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

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