Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
vu sach » su sach
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
han tai » hang tai, nhan tai, van tai
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa
va han » va phan, van han, va hanh

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