Perhaps you should try some spelling variations:
doan dau » doan dieu, phan dau, doan va
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu su » hieu sau, tieu su, hieu so
su kham » su pham, vu kham, so kham
thuc va » thuc vat, thuc dan, thuc day
dau cua » dai cua, day cua, cau cua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » truc va, tuc xa, duc va

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 ky nang ma hoi. hieu su kham ((tuc va) OR (thuc va)) doan dau cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ma hoi. hieu su kham ((tuc va) OR (thuc va)) doan dau cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ma hoi. hieu su kham ((tuc va) OR (thuc va)) doan dau cua tre*.