Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
tay lang » tai lang, tay tang, tay quang
doi cua » dai cua, hoi cua
van anh » van thanh, tuan anh
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
van hoi » van hoa, van hoc, van hoe
y lang » o lang, _ lang, yen lang
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((y lang) OR (tay lang)) van hoi. hieu ve tham thuc ((van anh) or (van minh)) doi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y lang) OR (tay lang)) van hoi. hieu ve tham thuc ((van anh) OR (van minh)) doi cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y lang) OR (tay lang)) van hoi. hieu ve tham thuc ((van anh) or (van minh)) doi cua tu*".