You are preparing a case study on the dallas cowboys. you use many methods of data collection in creating the case study. here is an excerpt:

the dallas cowboys were formed in 1960 and have had seven head coaches since then. i surveyed 100 people and one of the questions was, who is your favorite coach of the dallas cowboys? seventy people said tom landry, fifteen said jimmy johnson, five said bill parcells, and ten answered other. one of those who answered other was my brother. i asked him which coach was his favorite and he said, "barry switzer because he was the last one to win a championship." i knew he was kidding because he had a smirk on his face.

the excerpt relays information gathered from questionnaires, interviews, observations, and historical data. identify the information from the case study that was collected by each of the four methods.