Perhaps you should try some spelling variations:
bach tuoc » sach duoc, sach nuoc
hieu vien » hieu hien, hieu viec, thieu nien
cau tren » cu tren, dau tren, ca tren
toc sach » hoc sach, doc sach, thuoc sach
nang xa » nang x, lang xa, nang ma
va hang » van hang, va nang, va hanh
va lang » va nang, hoa lang
tu sach » thu sach, su sach, te sach
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: ((tu sach) or (toc sach)) ky nang xa hoi. hieu vien bach tuoc ((va hang) OR (va lang)) va cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky nang xa hoi. hieu vien bach tuoc ((va hang) OR (va lang)) va cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky nang xa hoi. hieu vien bach tuoc ((va hang) OR (va lang)) va cau tren".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky nang xa hoi. hieu vien bach tuoc ((va hang) OR (va lang)) va cau tren*.