[NTG-context] How change separator between two authors?

Hi, I use your bib module but in case of two authors I need comma as separator between them instead of 'and'. How can I change it? And additionally how can I do list of publications like that: [1] Entry ... [10] Entry (entry numbers aligned to right with []) instead of 1 Entry ... 10 Entry (entry numbers aligned to left) ?... -- Best regards, Martin