Perhaps you should try some spelling variations:
nhanh hai » nhanh thai, thanh hai, nhanh ha
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
va nhanh » va thanh, va hanh, va nhan
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang xa) or (nang ma)) hoi. hieu van cau duc va nhanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (nang ma)) hoi. hieu van cau duc va nhanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (nang ma)) hoi. hieu van cau duc va nhanh hai cua tre*.