Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tra nang » thi nang, kha nang, da nang
van hao » van dao, van ha, van bao
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
van cao » van dao, van bao, van cau
nang xa » nang x, lang xa, nang ma
va cua » va chua, via cua, ca cua
cua te » cua tu

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