How to implement left join in JOIN Extension method

I am trying to implement an outer join on this kind of query for the p.Person table. How would I do this?

This example is taken from http://ashishware.com/DSLinqExample.shtml

var onlyinfo = p.Person
    .Where(n => n.FirstName.Contains('a'))
    .Join(p.PersonInfo,
        n => n.PersonId,
        m => m.PersonId,
        (n, m) => m)
    .ToArray<Persons.PersonInfoRow>();