What is the marriage date for the Habsburg-Lorraine house member who died 29 December 1829?
CREATE TABLE "house_of_habsburg_lorraine_1765_1918" (
  "name" text,
  "birth" text,
  "marriage" text,
  "became_duchess" text,
  "ceased_to_be_duchess" text,
  "death" text,
  "spouse" text
);
SELECT "marriage" FROM "house_of_habsburg_lorraine_1765_1918" WHERE "death"='29 december 1829';