How can network effects lead the industry to become an oligopoly?

Abigail spent $100 on a new edition of the personal finance textbook rather than $75 for a used copy. the additional cost for the new copy is called the

How would you cite different books by the same author on the works cited page? a. moore, jack h. folk songs and ballads. salem: poetry press, 1999. print. moore, jack h. ballads in poetry – a critical review. dallas: garden books, 1962. print. b. moore, jack h. folk songs and ballads. salem: poetry press, 1999. print. –––. ballads in poetry – a critical review. dallas: garden books, 1962. print. c. moore, jack h. ballads in poetry – a critical review. dallas: garden books, 1962. print. moore, jack h. folk songs and ballads. salem: poetry press, 1999. print. d. moore, jack h. ballads in poetry – a critical review. dallas: garden books, 1962. print. –––. folk songs and ballads. salem: poetry press, 1999. print.

Alinguist had a gross income of 53,350 last year. if 17.9% of his income got witheld for federal income tax, how much of the linguist's pay got witheld for federal income tax last year?