Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
sach thu » sach thue, sach thieu, sach tham
thuc day » thuc dan, thuc vat
day hanh » day nhanh, day thanh, dao hanh
su sach » so sach, vu sach
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thu ((nang x) or (lang xa)) hoi. hieu ve cham thuc day hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((nang x) OR (lang xa)) hoi. hieu ve cham thuc day hanh vi cua tre*.