Perhaps you should try some spelling variations:
tuan vai » tuan tai, trang vai, tuan khai
nang mai » nang ma, nang tai, lang mai
soc van » hoc van, oc van, soc dan
vai cua » dai cua, hai cua, lai cua
sac van » cac van, san van, sat van
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
sach ty » sach tu, sach thu, xach tay
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet

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 ty) or (sach y)) nang mai hoi. hieu ve cham ((soc van) OR (sac van)) tuan vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach y)) nang mai hoi. hieu ve cham ((soc van) OR (sac van)) tuan vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach y)) nang mai hoi. hieu ve cham ((soc van) OR (sac van)) tuan vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach y)) nang mai hoi. hieu ve cham ((soc van) OR (sac van)) tuan vai cua tre*.