Generally all SNMP4J versions can be downloaded by using the following URL pattern:

http://www.snmp4j.org/snmp4j-<version>.zip

<version> is the version of the product which can be copied from the CHANGE LOG, for example 1.9.3d.

For SNMP4J-Agent the URL pattern is:

http://www.snmp4j.org/snmp4j-agent-<version>.zip