Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
cham luc » cham soc, nhan luc, cham cuu
hieu ve » hieu va, hieu van
luc van » luoc van, luu van, duc van
nang ma » tang ma, nang cao, mang may
ve cham » va cham, ve chat, vu cham
sang ma » tang ma, sang tao, mang may
sach ky » sach y, sach ty, sach kem
sac ky » cac ky, sai ky
vai va » mai va, dai va, hai 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: tu ((sach ky) or (sac ky)) ((nang ma) or (sang ma)) hoi. hieu ve cham luc van hanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) ((nang ma) OR (sang ma)) hoi. hieu ve cham luc van hanh vai va thiet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) ((nang ma) or (sang ma)) hoi. hieu ve cham luc van hanh vai va thiet*.