Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
lang van » dang van, tang van, hoang van
van hanh » van thanh, ban hanh, van ban
van hoi » van hoa, van hoc, van hoe
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
van anh » van thanh, van minh
vi cua » vai cua, di cua
cua te » cua tu
tuan » quan, tran, luan

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 _ lang van hoi. hieu ve tham thuc ((van hanh) or (((van anh) or (tuan anh)))) vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach _ lang van hoi. hieu ve tham thuc ((van hanh) OR (((van anh) OR (tuan anh)))) vi cua te.
• Adding a wildcard symbol may retrieve word variants: toc sach _ lang van hoi. hieu ve tham thuc ((van hanh) or (((van anh) or (tuan anh)))) vi cua te*.