You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Arnold_Schwarzenegger

Context:
Schwarzenegger has had a highly successful business career. Following his move to the United States, Schwarzenegger became a "prolific goal setter" and would write his objectives at the start of the year on index cards, like starting a mail order business or buying a new car – and succeed in doing so. By the age of 30, Schwarzenegger was a millionaire, well before his career in Hollywood. His financial independence came from his success as a budding entrepreneur with a series of successful business ventures and investments.

Question:
Where would Schwarzenegger write down his goals?

index cards