Perhaps you should try some spelling variations:
truc ngan » tu ngan, thu ngan, tri ngan
sach thu » sach thue, sach thieu, sach tham
hang vi » hang va, hanh vi, hang di
sach ty » sach y, sach tu, xach tay
ca tren » cau tren, cu tren, la tren
mang xa » lang xa, mang may, dang xay
ve cau » ke cau, ve cac, le cau
va cau » van cau, va cac, va dau
vi ca » vit ca, li ca, va ca

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 ty) OR (sach thu)) mang xa hoi. hieu ((ve cau) or (va cau)) truc ngan hang vi ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) mang xa hoi. hieu ((ve cau) OR (va cau)) truc ngan hang vi ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach thu)) mang xa hoi. hieu ((ve cau) or (va cau)) truc ngan hang vi ca tren".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach thu)) mang xa hoi. hieu ((ve cau) or (va cau)) truc ngan hang vi ca tren*.