Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
thu sach » tu sach, thuat sach, thuoc sach
toc sach » hoc sach, doc sach, thuoc sach
cau tren » cu tren, dau tren, ca tren
nang xa » nang x, lang xa, nang ma
tuoc va » thuoc va, nuoc va, tuc va
duoc va » nuoc va, duc va, duoc ma
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (toc sach)) ky nang xa hoi. hieu vien bach ((tuoc va) OR (duoc va)) hang va cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (toc sach)) ky nang xa hoi. hieu vien bach ((tuoc va) OR (duoc va)) hang va cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (toc sach)) ky nang xa hoi. hieu vien bach ((tuoc va) OR (duoc va)) hang va cau tren".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (toc sach)) ky nang xa hoi. hieu vien bach ((tuoc va) OR (duoc va)) hang va cau tren*.