Is Zhang Xueliang's calligraphy valuable? Is it true?/You don't say. /You don't say.

It seems to be a good calligraphy work. If it is Zhang Xueliang's, it is still not good, because even the basic strokes are not proficient, let alone cursive script, and ordinary calligraphers do not exist, let alone Zhang Xueliang. So, it is not Zhang Xueliang's. Judging from ordinary calligraphy works, many of his replies are not standardized. Let's just say it's not a sick pen. If it is Zhang Xueliang's, it is still valuable. But it's not!