Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dien cuc » dieu cua, vien cac, dien hoc
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
va danh » va dinh, va dan, va hanh
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
soc va » hoc va, loc va, doc va

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 xa hoi. ((hieu va) or (lieu va)) cham soc va danh ((dien cuc) OR (dien tu)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang xa hoi. ((hieu va) OR (lieu va)) cham soc va danh ((dien cuc) OR (dien tu)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v nang xa hoi. ((hieu va) or (lieu va)) cham soc va danh ((dien cuc) OR (dien tu)) te".
• Adding a wildcard symbol may retrieve word variants: toc sach v nang xa hoi. ((hieu va) or (lieu va)) cham soc va danh ((dien cuc) OR (dien tu)) te*.