What is the point classification with chris anker sørensen as the young rider classification and Christian vande velde as the general classification?
CREATE TABLE "classification_leadership" (
  "stage" text,
  "general_classification" text,
  "points_classification" text,
  "mountains_classification" text,
  "young_rider_classification" text
);
SELECT "points_classification" FROM "classification_leadership" WHERE "young_rider_classification"='chris anker sørensen' AND "general_classification"='christian vande velde';