Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thuc dan » thuc hanh, hoc dan, thuc vat
tay lang » tai lang, tay tang, tay quang
hanh va » hang va, hanh vi
thuc va » thuc vat, thuc day
te sach » toc sach
hieu ve » hieu va, hieu van
ty lang » ty xang, ty hang, tu lang
ve pham » vi pham, v pham, ve phan
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ty lang) or (tay lang)) xa hoi. hieu ve pham ((thuc va) OR (thuc dan)) hanh va cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty lang) OR (tay lang)) xa hoi. hieu ve pham ((thuc va) OR (thuc dan)) hanh va cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty lang) or (tay lang)) xa hoi. hieu ve pham ((thuc va) OR (thuc dan)) hanh va cua viet".
• Adding a wildcard symbol may retrieve word variants: te sach ((ty lang) or (tay lang)) xa hoi. hieu ve pham ((thuc va) OR (thuc dan)) hanh va cua viet*.