Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
va cham » va chat, va tham
vu cham » vu kham, tu cham, qua cham
sach lo » sach dao, sach doi, sach hoi
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
soc va » hoc va, loc va, doc va
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di 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 lo ((nang xa) or (nang ma)) hoi. hieu ((vu cham) OR (va cham)) soc va dan vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach lo ((nang xa) OR (nang ma)) hoi. hieu ((vu cham) OR (va cham)) soc va dan vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach lo ((nang xa) or (nang ma)) hoi. hieu ((vu cham) OR (va cham)) soc va dan vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach lo ((nang xa) or (nang ma)) hoi. hieu ((vu cham) OR (va cham)) soc va dan vi cua tre*.