Preheat oven to 325°. In a large mixing bowl, using an electric mixer, beat the cream cheese with the egg yolks until the mixture is completely smooth. Beat in the sugar, flour, sour cream, lemon juice, vanilla extract, lemon and orange rinds. Place the egg whites (at room temperature) and cream of tartar in a medium mixing bowl. Beat the whites with an electric mixer until they hold short, distinct peaks. Fold about one-third of the whites into the cream cheese mixture, thoroughly, to lighten it, then carefully fold in the rest.
Pour the mixture into an ungreased 9 or 10-inch springform pan. Bake at 325° for 1 hour and 10 minutes, or until the center no longer appears soft. (During the cooking, the cheesecake will puff up and then shrink and crack as it cools.) Let the cake cool completely (at least 2 hours) at room temperature before removing sides of pan. The cheesecake will keep, refrigerated, for 5 days. Serve topped with fresh strawberries. 10-12 servings.