Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cham hoc » cham soc, chat hoc, cham hoi
tuan vai » tuan tai, trang vai, tuan khai
nang mai » nang ma, nang tai, lang mai
van tuan » van quan, van ban, anh tuan
cua tre » cua te, cuu tre, dua tren
hoc van » hoc dan, hoc va, hoc vat
sach ty » sach tu, sach thu, xach tay
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ve cham » va cham, ve chat, vu cham

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 hoc van tuan vai ((cua tre) OR (cua triet))~.
• 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 hoc van tuan vai ((cua tre) OR (cua triet)).
• 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 hoc van tuan vai ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach y)) nang mai hoi. hieu ve cham hoc van tuan vai ((cua tre) OR (cua triet))*.