Perhaps you should try some spelling variations:
duong manh » duong van
thuoc sach » hoc sach, nuoc sach, thuat sach
tham thuc » nham thuc, pham thuc, tam thuc
hieu van » hieu va, thien van, lieu va
hanh doi » thanh doi, hanh noi, hang doi
van tham » van thanh, van tuan, van chat
sach van » sach han, sach va, bach van
duong ma » duong va, cuong ma, duong qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
doi cua » dai cua, hoi cua
cua te » cua tu

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 van ((duong ma) OR (duong manh)) hoi. hieu van tham thuc va hanh doi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach van ((duong ma) OR (duong manh)) hoi. hieu van tham thuc va hanh doi cua te".
• Adding a wildcard symbol may retrieve word variants: thuoc sach van ((duong ma) OR (duong manh)) hoi. hieu van tham thuc va hanh doi cua te*.