Investments - Short term invesmtments (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Notes to Financial Statements
Short-term U.S. treasury bills	$ 1,998,017	$ 1,996,815
Certificates of deposit	200,000	200,000
Total short-term investments	$ 2,198,017	$ 2,196,815

Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

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