Perhaps you should try some spelling variations:
sach tham » sach nha
van hanh » van thanh, ban hanh, van anh
sach hay » sach han, sach ha, sach nay
lang van » dang van, hoang van, giang van
tang van » dang van, hoang van, trong van
cau luc » cau truc, cau phuc
hanh di » hanh vi, hanh de, hang di
luc van » luoc van, luu van, duc van
hieu ve » hieu va, hieu van
ve cau » ke cau, va cau, ve cac
di cua » dai cua, doi cua, de cua
cua tu » cua tuc, cua su, cua cu

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 tham) or (sach hay)) ((lang van) or (tang van)) hoi. hieu ve cau luc van hanh di cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tham) OR (sach hay)) ((lang van) OR (tang van)) hoi. hieu ve cau luc van hanh di cua tu.
• Adding a wildcard symbol may retrieve word variants: tu ((sach tham) or (sach hay)) ((lang van) or (tang van)) hoi. hieu ve cau luc van hanh di cua tu*.