Perhaps you should try some spelling variations:
sach van » sach han, bach van, cach van
cam truc » cau truc, nam truc, lam truoc
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
sach va » sach xa, sach ha, sach dao
hieu ve » hieu va, hieu van
hanh te » hanh tu, hanh ve, hanh de
cua tre » cua te, cuu tre, cua triet
do hoi » do choi, do hoai, do thoi
ve cam » ve cham, ve cac, va cam
te cua » tue cua, le cua, de cua

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 van) or (sach va)) ban do hoi. hieu ve cam truc van hanh te cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach van) OR (sach va)) ban do hoi. hieu ve cam truc van hanh te cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach van) or (sach va)) ban do hoi. hieu ve cam truc van hanh te cua tre*.