Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham luc » cham soc, nhan luc, cham cuu
vu sach » vu bach, su sach, vu khach
hanh di » hanh vi, hanh de, hang di
luc van » luoc van, luu van, duc van
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sach ly » sach y, sach lo, sach ty
nang ma » tang ma, sang ma, nang cao
mang xa » lang xa, mang may, dang xay
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ly ((((nang x) or (mang xa))) or (nang ma)) hoi. hieu ve cham luc van hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ly ((((nang x) OR (mang xa))) OR (nang ma)) hoi. hieu ve cham luc van hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ly ((((nang x) or (mang xa))) or (nang ma)) hoi. hieu ve cham luc van hanh di cua tre*.