Could you please answer me the questions, thanks a lot.

Could you please answer me the following questions, these are from Microeconomics. Thanks a lot. 1.Sources: a. What is the definition of a valid and acceptable source for academic papers, projects, and presentations? List 3 examples of sources that are considered valid and acceptable for academic research, analysis, and presentations. b. What is the definition of an invalid and unacceptable source for academic papers, projects, and presentations? List 3 examples of sources that are considered invalid and unacceptable for academic research, analysis, and presentations. 4.Economic Systems: a.Explain the difference between a market-based economy and a planned/command-based economy? b. What are the 3 significant economic questions that each economic system must answer regardless of social-political-economic system? c. What is the significance of the sections of the US Constitution that specifically set forth the concept of individual property rights? d. What is the significance of individual property rights for economic development and growth?