Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
thanh van » thanh san, thanh phan, thanh nhan
tang mai » tang ma, tang tai, lang mai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
cam lo » nam lo, cam ly, cam o
y tang » ky tang, 6 tang, 7 tang
cham o » cham soc

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 y tang mai hoi. hieu van ((cham o) or (cam lo)) va ((thanh van) OR (thanh toan)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y tang mai hoi. hieu van ((cham o) OR (cam lo)) va ((thanh van) OR (thanh toan)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y tang mai hoi. hieu van ((cham o) or (cam lo)) va ((thanh van) OR (thanh toan)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y tang mai hoi. hieu van ((cham o) or (cam lo)) va ((thanh van) OR (thanh toan)) cua tre*.