Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
van cam » van nam, van lam, van cau
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
tuc va » thuc va, truc va, tuc xa
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky ((nang xa) or (nang x)) hoi. hieu van cam tuc va hanh tai cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky ((nang xa) OR (nang x)) hoi. hieu van cam tuc va hanh tai cua su.
• Adding a wildcard symbol may retrieve word variants: doc sach ky ((nang xa) or (nang x)) hoi. hieu van cam tuc va hanh tai cua su*.