Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
hieu van » hieu va, thien van, lieu va
cham tuc » nham thuc, pham thuc, tham thuc
danh vai » danh sai, danh va, doanh van
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va
va danh » va dinh, va dan, va hanh
vai cau » va cau, van cau, vai cac
tuc va » thuc va, truc va, tuc xa

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 thu nang xa hoi. ((hieu ve) or (hieu van)) cham tuc va danh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang xa hoi. ((hieu ve) OR (hieu van)) cham tuc va danh vai cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang xa hoi. ((hieu ve) or (hieu van)) cham tuc va danh vai cau tren*.