I'm a non-native English speaker at a California university absolutely fascinated by the variety of English accents I encounter in my day-to-day life. I have a co-worker with a Singaporean accent, for example, and hearing it in both her Chinese and English is just really cool.
While I have some formal linguistics training and can hypothesize certain phonological rules governing my peers' accents, I was wondering if there exists any kind of encyclopedia or authoritative resource regarding the formal elements of the accents of non-native English speakers, or regional English accents. I'd like to have a more structured understanding of the accents around me, so that I might, for example, more precisely think about and describe my Mandarin speaking coworker's "abrupt" English, or the pitch structure in the sentences of my Vietnamese coworker, and be able to reproduce these accents myself (as an exercise, and to blend into certain communities when appropriate).
I see plenty of anecdotal examples in introductory phonology texts, e.g., metathesis in AAVE, glottal stops in the L2 English of native Vietnamese speakers, etc., but is there a resource that compiles this information, such that I could search a particular language and it would provide phonological information?