Happy Birthday, Isabella (S04E19)

S04E01 For Your Ice Only S04E02 Happy New Year! S04E03 Fly on the Wall S04E04 Bully Bust S04E05 My Sweet Ride S04E06 Der Kinderlumper S04E07 Sidetracked S04E08 Primal Perry S04E09 Mind Share S04E10 Backyard Hodge Podge S04E11 Bee Day S04E12 Bee Story S04E13 Great Balls of Water S04E14 Where's Pinky? S04E15 Phineas and Ferb's Musical Cliptastic Countdown Hosted by Kelly Osbourne S04E16 Knot My Problem S04E17 Just Desserts S04E18 La Candace-Cabra S04E19 Happy Birthday, Isabella S04E20 Love at First Byte S04E21 One Good Turn S04E22 Phineas and Ferb: Mission Marvel S04E23 Thanks But No Thanks S04E24 Troy Story S04E25 Druselsteinoween S04E26 Terrifying Tri-State Trilogy of Terror S04E27 Face Your Fear S04E28 Cheers for Fears S04E29 Steampunx S04E30 Just Our Luck S04E31 Return Policy S04E32 Live and Let Drive S04E33 Phineas and Ferb Save Summer S04E34 Father's Day S04E35 Imperfect Storm S04E36 The Return of the Rogue Rabbit S04E37 It's No Picnic S04E38 The Klimpaloon Ultimatum S04E39 Operation Crumb Cake S04E40 Mandace S04E41 Phineas and Ferb: Star Wars S04E42 Lost in Danville S04E43 The Inator Method S04E44 Night of the Living Pharmacists S04E45 Tales from the Resistance: Back to the 2nd Dimension S04E46 Doof 101 S04E47 Act Your Age S04E48 Last Day of Summer