Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham duc » pham duc, cham soc, pham duy
dien cuc » dien tu, dieu cua, vien cac
dien cua » dieu cua, dien cu, tien cua
tai khoi » tai khoa, mai khoi, tao khoi
va danh » va dinh, va dan, va hanh
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
tai hoi » dai hoi, tai hai, tai hoe
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach v nang ((tai hoi) or (tai khoi)). hieu vu cham duc va danh ((dien cua) OR (dien cuc)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang ((tai hoi) OR (tai khoi)). hieu vu cham duc va danh ((dien cua) OR (dien cuc)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v nang ((tai hoi) or (tai khoi)). hieu vu cham duc va danh ((dien cua) OR (dien cuc)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach v nang ((tai hoi) or (tai khoi)). hieu vu cham duc va danh ((dien cua) OR (dien cuc)) tre*.