Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
nang ma » sang ma, nang cao, mang may
tang ma » mang may, tang van
va cam » va cham, va cac, va cao
vi cua » vai cua, di cua
ve cam » ve cham, ve cac, ve cai

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 y ((nang ma) OR (tang ma)) hoi. hieu ((ve cam) or (va cam)) thuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang ma) OR (tang ma)) hoi. hieu ((ve cam) OR (va cam)) thuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang ma) OR (tang ma)) hoi. hieu ((ve cam) or (va cam)) thuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang ma) OR (tang ma)) hoi. hieu ((ve cam) or (va cam)) thuc va hanh vi cua tre*.