Perhaps you should try some spelling variations:
sach tao » sach bao, sach tai, sach tham
dua tren » dung tren
van hanh » van thanh, ban hanh, van anh
sach dao » lanh dao
nano cau » nang cau, bang cau, nano va
luc van » luoc van, luu van, duc van
cuu tre » cua tre, cau tren, cau treo
cam luc » cam xuc, cau luc
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach tao) or (sach dao)) nano cau hoi. hieu ve cam luc van hanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach tao) OR (sach dao)) nano cau hoi. hieu ve cam luc van hanh vi ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su ((sach tao) or (sach dao)) nano cau hoi. hieu ve cam luc van hanh vi ((dua tren) or (cuu tre))*.