4. Fair Value of Financial Instruments (Details) - USD ($)	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Assets:
Cash and cash equivalents	$ 1,358,100	$ 1,053,100	$ 700,700	$ 1,025,100
Available for sale securities	307,800	314,700
Total	1,665,900	1,367,800
Liabilities:
Contingent consideration	408,000	408,000
Level 1
Assets:
Cash and cash equivalents	1,358,100	1,053,100
Available for sale securities	307,800	314,700
Total	1,665,900	1,367,800
Liabilities:
Contingent consideration	0	0
Level 2
Assets:
Cash and cash equivalents	0	0
Available for sale securities	0	0
Total	0	0
Liabilities:
Contingent consideration	0	0
Level 3
Assets:
Cash and cash equivalents	0	0
Available for sale securities	0	0
Total	0	0
Liabilities:
Contingent consideration	$ 408,000	$ 408,000