Perhaps you should try some spelling variations:
day hanh » day nhanh, day thanh, dao hanh
lang dai » lang mai, lang chai, hoang dai
thuc day » thuc dan, thuc vat
lang hai » lang chai, lang thai, lang ha
bo sach » co sach, hoc sach
ve cham » va cham, ve chat, vu cham
sach va » sach xa, sach ha, sach dao
va viet » hoa viet, san viet, mai viet
ve cam » ve cac, va cam, ve cai
vi va » vi van, vai va, vu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach va ((lang dai) or (lang hai)) hoi. hieu ((ve cam) or (ve cham)) thuc day hanh vi va viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach va ((lang dai) OR (lang hai)) hoi. hieu ((ve cam) OR (ve cham)) thuc day hanh vi va viet.
• Adding a wildcard symbol may retrieve word variants: bo sach va ((lang dai) or (lang hai)) hoi. hieu ((ve cam) or (ve cham)) thuc day hanh vi va viet*.