Perhaps you should try some spelling variations:
van quang » van quan, tran quang, van tuan
cau tren » cu tren, dau tren, ca tren
van nang » van ban, van dong, van dung
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
hanh de » hanh ve, hanh kem
so sach » so sanh, bo sach, co sach
le nam » ly nam, he nam, le na
de cau » ke cau, le cau, ve cau
ve nam » he nam, va nam, te nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((van nang) or (van quang)) x ho. hieu ((ve nam) or (le nam)) truc van hanh de cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((van nang) OR (van quang)) x ho. hieu ((ve nam) OR (le nam)) truc van hanh de cau tren.
• Adding a wildcard symbol may retrieve word variants: so sach ((van nang) or (van quang)) x ho. hieu ((ve nam) or (le nam)) truc van hanh de cau tren*.