What are all approximate sales for the author Laura Ingalls Wilder?
CREATE TABLE "between_50_million_and_100_million_copie" (
  "book_series" text,
  "author" text,
  "original_language" text,
  "no_of_installments" text,
  "first_published" text,
  "approximate_sales" text
);
SELECT "approximate_sales" FROM "between_50_million_and_100_million_copie" WHERE "author"='Laura Ingalls Wilder';