My workbook notes for this research point [click on each page to enlarge]:
Part 4 Project 6 Exercise 1 – research point 1, page 1Part 4 Project 6 Exercise 1 – research point, page 2Part 4 Project 6 Exercise 1 – research point, page 3Part 4 Project 6 Exercise 1 – research point, page 4Part 4 Project 6 Exercise 1 – research point, page 5