Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va cham » va chat, va tham
luc van » luoc van, luu van, duc van
van han » van hanh, van phan, van nhan
han tai » hang tai, nhan tai, van tai
tai va » thai va, mai va, tri va
thiet » thieu

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 ky ((nang xa) OR (lang xa)) hoi. hieu va cham luc van han tai va thiet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang xa) OR (lang xa)) hoi. hieu va cham luc van han tai va thiet".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang xa) OR (lang xa)) hoi. hieu va cham luc van han tai va thiet*.