Perhaps you should try some spelling variations:
van nhanh » van thanh, van hanh, van khanh
nhanh hai » nhanh thai, thanh hai, nhanh ha
sach moi » sach hoi, bach mai, sach bai
sach doi » sach hoi, sach dao, sach bai
hai cua » thai cua, dai cua, hoi cua
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
nang xa » nang x, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach doi) OR (sach moi)) ((nang xa) or (lang xa)) hoi. hieu va cam duc van nhanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach doi) OR (sach moi)) ((nang xa) OR (lang xa)) hoi. hieu va cam duc van nhanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach doi) OR (sach moi)) ((nang xa) or (lang xa)) hoi. hieu va cam duc van nhanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach doi) OR (sach moi)) ((nang xa) or (lang xa)) hoi. hieu va cam duc van nhanh hai cua tre*.