Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
thu sach » tu sach, thuat sach, thuoc sach
hieu voi » hieu moi, lieu voi, hieu loi
voi pham » vi pham, toi pham, loai pham
so sach » so sanh, bo sach, co sach
loi cua » loai cua, hoi cua, lai cua
doi cua » dai cua, hoi cua
nang o » nang co, nang ho, nang ro
o hoc » co hoc, mo hoc, so hoc

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) or (so sach)) ky nang o hoc. hieu voi pham duc tan thanh ((loi cua) OR (doi cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (so sach)) ky nang o hoc. hieu voi pham duc tan thanh ((loi cua) OR (doi cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (so sach)) ky nang o hoc. hieu voi pham duc tan thanh ((loi cua) OR (doi cua)) te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (so sach)) ky nang o hoc. hieu voi pham duc tan thanh ((loi cua) OR (doi cua)) te*.