% 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 '83.145.29.32 - 83.145.29.63'

% Abuse contact for '83.145.29.32 - 83.145.29.63' is 'abuse@ip-only.net'

inetnum:        83.145.29.32 - 83.145.29.63
netname:        S1NET-CUSTOMERS
descr:          S1 Networks Oy / Shared Customer Block
country:        FI
admin-c:        SNO23-RIPE
tech-c:         SNO23-RIPE
status:         ASSIGNED PA
mnt-by:         IP-ONLY-MNT
created:        2012-11-13T14:27:57Z
last-modified:  2016-04-25T12:10:13Z
source:         RIPE

role:           S1 Networks NOC
admin-c:        MK19047-RIPE
admin-c:        TW2611-RIPE
tech-c:         MK19047-RIPE
tech-c:         TW2611-RIPE
address:        Lemuntie 7 A
address:        00510 Helsinki
address:        Finland
nic-hdl:        SNO23-RIPE
mnt-by:         S1-MNT
created:        2016-03-11T09:09:04Z
last-modified:  2019-07-31T16:50:08Z
source:         RIPE # Filtered

% Information related to '83.145.0.0/18AS12552'

route:          83.145.0.0/18
descr:          IP-ONLY
origin:         AS12552
mnt-by:         IP-ONLY-MNT
created:        2018-10-05T11:12:22Z
last-modified:  2018-10-05T11:12:22Z
source:         RIPE

% Information related to '83.145.0.0/18AS24862'

route:          83.145.0.0/18
descr:          IP-ONLY
origin:         AS24862
mnt-lower:      IP-ONLY-MNT
mnt-routes:     IP-ONLY-MNT
mnt-by:         IP-ONLY-MNT
created:        2004-02-02T10:58:31Z
last-modified:  2012-10-25T12:09:14Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.112 (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