宾夕法尼亚大学沃顿商学院的Prof.Monique Guignard 在给李端教授的信中表达对孙老师的哀悼。

Dear Duan,

I know you were a very close friend of Xiaoling. I just wanted to tell you how sad I am that he succombed to this terrible illness. We both lost a wonderful friend and a great human being.

-Monique

The following photo are shared by Prof. Prof. Monique Guignard-Spielberg