Combine multiple events for reporting

Hi,

I'm using splunk for caching the log and reporting, now I need to query in splunk for user action and generate a report. My case will be showed as following

I had several events in a log like :

• e1: [email1@test.com] Login system with username:email1

• e2: [email1@test.com] Read articleId:art1

• e3: [email1@test.com] Read articleId:art2

• e4: [anotheremail1@test.com] Login system with username:email2

Now I want to list all actions made by user who read article with articleId is art1. Which search statement can help me?