Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
danh di » danh du, xanh di, danh dien
thuc va » thuc vat, thuc dan, thuc day
cuu tre » cau tren, cau treo
van cac » van hac, van cau, van bac
nang ma » tang ma, sang ma, nang cao
tuc va » truc va, tuc xa, duc va
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ma hoi. hieu van cac ((tuc va) or (thuc va)) danh di ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. hieu van cac ((tuc va) OR (thuc va)) danh di ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. hieu van cac ((tuc va) or (thuc va)) danh di ((cua tre) or (cuu tre))*.