Perhaps you should try some spelling variations:
gianh lai » gian lan
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
va gianh » va gian, van giang, va giai
van pham » san pham, van phan, van phat
lai cua » dai cua, hai cua, lai chau
ky bang » ky nang, ky dang, ke bang
tay hoi » tao hoi, tay thai
cua te » cua tu
tay ho » tay co, tay o, tay khao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) ky bang ((tay hoi) or (tay ho)). hieu van pham duc va gianh lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky bang ((tay hoi) OR (tay ho)). hieu van pham duc va gianh lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky bang ((tay hoi) or (tay ho)). hieu van pham duc va gianh lai cua te".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky bang ((tay hoi) or (tay ho)). hieu van pham duc va gianh lai cua te*.