Perhaps you should try some spelling variations:
va gianh » va gian, van giang, va giai
cham duc » pham duc, cham soc, pham duy
te sach » toc sach
hieu vu » hieu va, hieu ve, hieu su
lai cua » hai cua, lai chau, thai cua
vu cham » va cham, vu kham, tu cham
sach ky » sac ky, sach y, sach ty
tay hoi » tao hoi, tay thai
ky bang » ky nang, ky dang, ke bang
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 ky bang ((tay hoi) OR (tay ho)). hieu vu cham duc va gianh ((lai cua) or (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky bang ((tay hoi) OR (tay ho)). hieu vu cham duc va gianh ((lai cua) OR (dai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky bang ((tay hoi) OR (tay ho)). hieu vu cham duc va gianh ((lai cua) or (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: te sach ky bang ((tay hoi) OR (tay ho)). hieu vu cham duc va gianh ((lai cua) or (dai cua)) te*.