These entries are queried from radb.net using whois, you can try my project getting these.
:AS-IMSYS as-set: AS-IMSYS descr: IMSYS Autonomus systems SET remarks: ------ Start AS-SET -------- members: AS29319 remarks: AS-IMSYS members: AS57085 remarks: SUNNET members: AS61410 remarks: SUNNET-CLIENT members: AS58319 descr: Kazakov-AS members: AS44269 descr: GELIOS-AS members: AS42482 descr: ASN-IMSYS-NN members: AS62450 descr: TELECOMPROEKT-AS members: AS57045 descr: SPECSVYAZ-AS members: AS44927 descr: TELECOM-MPK-AS members: AS-LOGITEL descr: LOGITEL-AS members: AS199809 descr: MAKSTEL-AS members: AS41223 descr: SPM-LTD-AS members: AS-BITRACE descr: BITRACE members: AS43319 descr: GP-INTERNET members: AS-INTERLAN descr: INTERLAN members: AS-CHIP-TELECOM descr: CHIP-TELECOM members: AS50471 descr: SVYAZ-INDUSTRIYA members: AS197498 descr: VERBETA remarks: ------ End AS-SET -------- tech-c: DUMY-RIPE admin-c: DUMY-RIPE mnt-by: IMSYS-MNT created: 2004-10-05T10:06:34Z last-modified: 2023-10-02T05:55:45Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: ****************************