Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thien van » thi van
hanh tai » thanh tai, hang tai, han tai
cau thuc » cau truc, cuu thuc, can thuc
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
sach ky » sac ky, sach y, sach ty
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
cua tre » cua te, cuu tre, cua triet

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