Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
lang ha » long ha
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
luu tre » luu tru, cuu tre, luy tre
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 luu » vi lua

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 ky ((nang x) or (lang ha)) hoi. hieu va cam duc va dan vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky ((nang x) OR (lang ha)) hoi. hieu va cam duc va dan vi luu tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((nang x) or (lang ha)) hoi. hieu va cam duc va dan vi luu tre*.