Perhaps you should try some spelling variations:
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, ve cai
va cam » va cham, va cac, va cao
di cua » dai cua, doi 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 nang x ho. hieu ((ve cam) or (va cam)) truc van hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach van nang x ho. hieu ((ve cam) OR (va cam)) truc van hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach van nang x ho. hieu ((ve cam) or (va cam)) truc van hanh di cua tre*.