Words’ meaning:

1-Crisis:A crisis is a situation in which something or someone is affected by one or more very serious problems.

https://www.collinsdictionary.com/dictionary/english/crisis

2-Citation:A “citation” is the way you tell your readers that certain material in your work came
from another source. It also gives your readers the information necessary to find the
location details of that source on the reference or Works Cited page 

https://www.marian.edu/docs/default-source/marian's-adult-programs-documents/what-is-citation.pdf?sfvrsn=76a375fd_2

3-Scarcity:the quality or state of being scarce

https://www.merriam-webster.com/dictionary/scarcity

4-Shortage:A shortage is a lack of something, especially a severe lack. A drought is a shortage of water

https://www.vocabulary.com/dictionary/shortage

Sources (Citation)