Perhaps you should try some spelling variations:
nang mai » nang ma, lang mai, nang cai
van hanh » van thanh, ban hanh, van anh
nang tai » hang tai, tang tai, sang tai
cham luc » cham soc, nhan luc, cham cuu
va cham » va chat, va tham
hanh ki » hanh vi, hanh ky, hanh kien
luc van » luoc van, luu van, duc van
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
sach vu » sach va, sach tu, sach uu
su viet » so viet
ki su » ky su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu ((nang mai) OR (nang tai)) hoi. hieu va cham luc van hanh ki su viet~.
• Adding a wildcard symbol may retrieve word variants: tu sach vu ((nang mai) or (nang tai)) hoi. hieu va cham luc van hanh ki su viet*.