% APNIC found the following authoritative answer from: whois.ripe.net

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://apps.db.ripe.net/docs/HTML-Terms-And-Conditions

% Note: this output has been filtered.
%       To receive output for a database update, use the "-B" flag.

% Information related to '91.218.232.0 - 91.218.235.255'

% Abuse contact for '91.218.232.0 - 91.218.235.255' is 'alexnvis@gmail.com'

inetnum:        91.218.232.0 - 91.218.235.255
netname:        AGNET-NETWORK
country:        CZ
org:            ORG-SPER1-RIPE
admin-c:        SPER1-RIPE
tech-c:         SPER1-RIPE
status:         ASSIGNED PI
mnt-by:         RIPE-NCC-END-MNT
mnt-by:         SPERL-MNT
mnt-routes:     SPERL-MNT
mnt-domains:    SPERL-MNT
created:        2010-08-18T14:53:10Z
last-modified:  2016-04-14T11:14:58Z
source:         RIPE
sponsoring-org: ORG-Vs35-RIPE

organisation:   ORG-SPER1-RIPE
org-name:       Jiri Sperl
country:        CZ
org-type:       OTHER
address:        Zizkova 89, 349 01, Stribro, Czech Republic
abuse-c:        AR30554-RIPE
mnt-ref:        SPERL-MNT
mnt-by:         SPERL-MNT
created:        2010-08-03T14:24:28Z
last-modified:  2022-12-01T16:53:02Z
source:         RIPE # Filtered

person:         Jiri Sperl
address:        Zizkova 89, 349 01, Stribro, Czech Republic
phone:          +420603951403
nic-hdl:        SPER1-RIPE
mnt-by:         SPERL-MNT
created:        2010-08-03T14:21:27Z
last-modified:  2019-01-15T14:22:56Z
source:         RIPE

% Information related to '91.218.232.0/23AS51424'

route:          91.218.232.0/23
descr:          Jiri Sperl route
origin:         AS51424
mnt-by:         SPERL-MNT
created:        2010-08-30T14:32:59Z
last-modified:  2010-08-30T14:32:59Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.111 (ABERDEEN)

Search for
IP address lookups			Miscellaneous queries
-l	1st level less specific		-i	Inverse attributes	None admin-c admin-c,tech-c,zone-c author cross-mnt cross-nfy local-as mbrs-by-ref member-of mnt-by mnt-lower mnt-nfy mnt-routes notify nserver origin person referral-by rev-srv sub-dom tech-c upd-to zone-c
-L	All less specific		-T	Object types	All as-block as-set aut-num domain filter-set inet-rtr inet6num inetnum irt key-cert mntner peering-set person role route route-set rtr-set
-m	1st level more specific
-M	All more specific		Query hints Include "AS" in front of an AS number. Example: AS4808 Include "-t" (template only) or "-v" (template and description) in front of an object name to view the template Example: -t inetnum
-x	Exact match only
-d	Associated reverse domain