reference stationary slight php?

in php, i am means normal duty non-static but problem, nonetheless i haven't figured out stationary method. am i only blank right syntax, possible?

(edit: initial suggested answer does seem work. i've extended instance arrangement errors returned.)

function foo1($a,$b) { relapse $a/$b; }

class bar
{
    stationary duty foo2($a,$b) { relapse $a/$b; }

    open duty usereferences()
    {
        // works fine:
        $fn = foo1;
        imitation $fn(1,1);

        // works fine:
        imitation self::foo2(2,1);
        imitation bar::foo2(3,1);

        // does work ... error: capricious category consistent 'foo2'
        //$fn = self::foo2;
        //print $fn(4,1);

        // does work ... error: capricious duty self::foo2()
        //$fn = 'self::foo2';
        //print $fn(5,1);

        // does work ... error: capricious duty bar::foo2()        
        //$fn = 'bar::foo2';
        //print $fn(5,1);

     }
}

$x = new bar();
$x->usereferences();

(i am controlling php v5.2.6 -- does answer change depending chronicle too?)