Share-based payments (Details) - USD ($)	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Share-based payments
Nonemployee warrants - fully-vested upon issuance	$ 0	$ 32,624
Total share-based expense charged against income	$ 0	$ 32,624
Impact on net loss per common share: Basic and diluted	$ (0.00)	$ (0.00)

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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