Perhaps you should try some spelling variations:
thien van » thi van
toc sach » hoc sach, doc sach, thuoc sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cao hoi » cau hoi, co hoi, cao hoc
van cac » van hac, van cau, van bac
hang di » hang doi, hang vi, hang dien
di cua » dai cua, doi cua, de cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang cao hoi. thien van cac ((day va) OR (duc va)) hang di cua vat~.
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang cao hoi. thien van cac ((day va) or (duc va)) hang di cua vat*.