Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
vu sach » vu bach, su sach
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
lang ha » long ha
va cam » va cham, va cac, va cao
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi cuu » vi luu, vinh cuu

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) OR (vu khach)) ky ((nang x) or (lang ha)) hoi. hieu va cam duc va dan vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) ky ((nang x) OR (lang ha)) hoi. hieu va cam duc va dan vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (vu khach)) ky ((nang x) or (lang ha)) hoi. hieu va cam duc va dan vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) OR (vu khach)) ky ((nang x) or (lang ha)) hoi. hieu va cam duc va dan vi cuu tre*.