Note 10 - Shareholders' Equity - Fair Value Assumption of Warrant (Details) - $ / shares |
12 Months Ended | |||||
---|---|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2020 |
Jun. 30, 2017 |
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Warrants issued (in shares) | 5,830,000 | 500,000 | ||||
Exercise price (in dollars per share) | [1] | $ 0.75 | $ 0.54 | $ 0.75 | ||
Warrant [Member] | ||||||
Weighted average fair value (in dollars per share) | $ 0.51 | $ 0.41 | ||||
Warrants issued (in shares) | 5,830,000 | 500,000 | ||||
Expected term (in years) (Year) | 5 years 182 days | |||||
Risk-free rate | 2.74% | |||||
Volatility | 102.73% | |||||
Warrant [Member] | Minimum [Member] | ||||||
Exercise price (in dollars per share) | $ 0.75 | $ 0.01 | ||||
Expected term (in years) (Year) | 2 years | |||||
Risk-free rate | 1.62% | |||||
Volatility | 60.00% | |||||
Warrant [Member] | Maximum [Member] | ||||||
Exercise price (in dollars per share) | $ 0.9375 | $ 0.54 | ||||
Expected term (in years) (Year) | 3 years | |||||
Risk-free rate | 2.55% | |||||
Volatility | 82.00% | |||||
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