Condensed Consolidated Balance Sheets (unaudited) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 6,029,964	$ 4,763,364
Short term investments	45,115,391	44,254,862
Accounts receivable	4,663,282	3,810,792
Income tax receivable	290,205	494,711
Deferred royalty buy-down	1,535,274	1,451,893
Prepaid expenses and other current assets	800,547	624,345
Total current assets	58,434,663	55,399,967
Long-term investments	7,396,902	3,771,380
Deferred royalty buy-down - long term, net	1,156,242	1,976,456
Deferred tax assets, net	3,072,116	3,290,122
Patent costs, net	238,030	258,355
Total assets	70,297,953	64,696,280
Current liabilities:
Accounts payable and accrued expenses	1,162,497	738,649
Deferred revenue	1,298,912	1,179,848
Accrued liabilities of discontinued operations	78,138	78,138
Total current liabilities	2,539,547	1,996,635
Long-term deferred revenue	5,661,179	6,417,702
Stockholders' equity:
Series A Preferred stock, $.50 par value, 700,000 shares authorized; none outstanding	0	0
Common stock, $.001 par value; 10,000,000 shares authorized; 7,575,167 and 7,555,167 shares issued, 7,166,998 and 7,156,281 shares outstanding as of June 30, 2017 and December 31, 2016, respectively	7,575	7,555
Additional paid-in capital	33,270,422	32,945,240
Retained earnings	36,579,693	30,610,849
Treasury stock, 408,169 and 398,886 shares at cost as of June 30, 2017 and December 31, 2016, respectively	(7,760,463)	(7,281,701)
Total stockholders' equity	62,097,227	56,281,943
Total liabilities and stockholders' equity	$ 70,297,953	$ 64,696,280

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.