Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
va cham » va chat, va tham
ve cham » ve chat, vu cham, ve chim
long ha » dong ha, cong ha, dong hoa
ky long » ky cong, sy long, ky trong
su hien » su kien, su tien, thu hien
ha hoi » hoa hoi, ha noi, xa hoi

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 ky long ha hoi. hieu ((ve cham) or (va cham)) thuc va danh vi ((cua tre) or (su hien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky long ha hoi. hieu ((ve cham) OR (va cham)) thuc va danh vi ((cua tre) OR (su hien)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky long ha hoi. hieu ((ve cham) or (va cham)) thuc va danh vi ((cua tre) or (su hien))*.