Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
pham thuc » phap thuc, pham chuc, nham thuc
thien van » thi van
dinh dau » dinh dat, dinh du, danh dau
van pham » san pham, van phan, van phat
nang ma » tang ma, sang ma, nang cao
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
nang xa » nang x, lang xa, mang xa
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren

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 y ((nang xa) or (nang ma)) hoi. thien van pham thuc va dinh dau ((cuu tre) OR (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach y ((nang xa) OR (nang ma)) hoi. thien van pham thuc va dinh dau ((cuu tre) OR (cua tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach y ((nang xa) or (nang ma)) hoi. thien van pham thuc va dinh dau ((cuu tre) OR (cua tre))".
• Adding a wildcard symbol may retrieve word variants: thuoc sach y ((nang xa) or (nang ma)) hoi. thien van pham thuc va dinh dau ((cuu tre) OR (cua tre))*.