Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
xang xay » dang xay, van xay, xang dau
xay phoi » cay phoi, cap phoi, tay hoi
hieu van » hieu va, thien van, lieu va
sach ty » sach y, sach tu, sach thu
van lam » van nam
cua tre » cuu tre, cua triet, dua tren
luc va » tuc va, loc va
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ty xang xay phoi. hieu van lam ((luc va) or (duc va)) hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty xang xay phoi. hieu van lam ((luc va) OR (duc va)) hanh vi ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: toc sach ty xang xay phoi. hieu van lam ((luc va) or (duc va)) hanh vi ((cua tre) or (cua te))*.