. . "Eddington\u2013Finkelstein-type" . "Eddington\u2013Finkelstein form" . "Eddington–Finkelstein coordinates" . "Eddington\u2013Finkelstein coordinates" . "Eddington\u2013Finkelstein null coordinates" . . "tortoise coordinate" . . . . . "Eddington\u2013Finkelstein coordinates" .