Perhaps you should try some spelling variations:
sang tao » hang tai
su sach » so sach, vu sach
tai cua » thai cua, tai cuc, dai cua
va nang » van nang, da nang, cam nang
cac toc » cac toi, cac nuoc, cac thoi
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
ve cac » va cac, vien cac
toc va » hoc va, toc ta, tuc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang ma) or (sang tao)) hoi. hieu ve cac toc va nang ((tai cua) OR (tri cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang ma) OR (sang tao)) hoi. hieu ve cac toc va nang ((tai cua) OR (tri cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang ma) or (sang tao)) hoi. hieu ve cac toc va nang ((tai cua) OR (tri cua)) te".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang ma) or (sang tao)) hoi. hieu ve cac toc va nang ((tai cua) OR (tri cua)) te*.