The version of flow-typed for Jest is v24.x.x, but we use v26.

The new icon used for DOIs is confusing since the chain icon is crossed out.
Furthermore, the DOI icon in the entries is inconsistent with the DOI icon in the header.

Suggestion: Either revert the icon back or use a normal chain icon.
Furthermore, make the DOI icon used in the header and entries consistent.

![image](https://user-images.githubusercontent.com/43381984/91891570-8ee4e500-ec91-

When I draw a double line without arrow head, it produces \arrow[r, no head, Rightarrow] but compiling it with latex, I get a double line with head. It looks like the correct option is equal instead of no head, Rightarrow.