Ambigram: Symmetrical Text Design

Hello Guys~

Here is something I came across while reading Dan Brown's old novel Demon & Angel, the ambigram. In the Dan Brown's offiical website gives a little bit of introduction of what it is,
and here is the link.

According to Wiki's definition, Ambigram is "sometimes known as an inversion or flipscript, is a graphical figure that spells out a word not only in its form as presented, but also in another direction or orientation. The text can also consist of a few words, and the text spelled out in the other direction or orientation is often the same, but can also be a different text. Douglas R. Hofstadter describes an ambigram as a "calligraphic design that manages to squeeze two different readings into the selfsame set of curves." The term "ambigram" was first used to mean "ambiguous anagram" by Judith E. Bagai, a former editor of The Enigma, the official organ of The National Puzzlers' League."