Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
hieu van » hieu va, thien van, lieu va
dau thuc » dan thuc, dai thuc, dam thuc
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
dau tren » dau tien, dat tren, dau tieng
ly nang » ky nang, ly hang, ly vang
van dau » van dao, phan dau
y nang » ky nang, v nang, may nang
vi dau » vi dai, va dau, bi dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu khach ((y nang) or (ly nang)) xa hoi. hieu van dau thuc van hanh vi dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khach ((y nang) OR (ly nang)) xa hoi. hieu van dau thuc van hanh vi dau tren.
• Adding a wildcard symbol may retrieve word variants: vu khach ((y nang) or (ly nang)) xa hoi. hieu van dau thuc van hanh vi dau tren*.