market neutral / systematic credit resources

Hello

I've been working on buyside for last 3 years and have made some investments in the credit space. My mainstay is equities but we did have a few opportunities that came up we decided to opportunistically pursue. I've been receiving interest from recruiters from both multimanager PMs and some quant funds that are expanding their credit teams. Its an interesting area and I may consider a move into the space.

I want to ask WSO if credit specialists have any resources (books, websites, twitter handles, blogs etc) that are good resources for long/short and systematic credit?

Also, does anyone have a good description of how long/short credit differs from systematic credit? A lot of groups of spoken to still seem to trade manually even for so-called 'systematic'?