Note 8 - Research and Development	9 Months Ended
Jan. 31, 2023
Notes to Financial Statements
Research, Development, and Computer Software Disclosure [Text Block]	8. Research and Development: We invested in research and development activities. The amount invested in the nine months ended January 31, 2023 and 2022 was $2.3 million and $1.9 million, respectively.

The entire disclosure for research, development, and computer software activities, including contracts and arrangements to be performed for others and with federal government. Includes costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility and in-process research and development acquired in a business combination consummated during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 730
-URI https://asc.fasb.org/subtopic&trid=2197926

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