Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » hieu va, thien van, lieu va
van chat » cao chat
cua tre » cua te, cua triet, dua tren
danh di » danh du, xanh di, danh dien
cuu tre » cau tren, cau treo
sach ky » sac ky, sach y, sach ty
truc va » thuc va, trung va
nang xa » nang x, lang xa, nang ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky nang xa hoi. hieu van chat ((truc va) or (thuc vat)) danh di ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky nang xa hoi. hieu van chat ((truc va) OR (thuc vat)) danh di ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky nang xa hoi. hieu van chat ((truc va) or (thuc vat)) danh di ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky nang xa hoi. hieu van chat ((truc va) or (thuc vat)) danh di ((cua tre) OR (cuu tre))*.