To decide when to stop collecting material in a literature ...

[JGIBBSON]

To decide when to stop collecting material in a literature review, one should
 
  a. continue until no more material can be found.
  b. determine if there is an appropriate proportion of information from both journal and book sources.
  c. examine the foundation laid by the review for one's question.
  d. observe the number of sources retrieved.

Question 2

To find all materials indexed by a given resource that deals with deaf education outside of the United States, you would use
 
  a. deaf education and United States. c. deaf education, not United States.
  b. deaf education or United States. d. None of these answers.

[braelync]

Answer to Question 1

C

Answer to Question 2

C

[JGIBBSON]

Thank you!

[braelync]

Happy to help