% 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://docs.db.ripe.net/terms-conditions.html

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

% Information related to '5.142.44.0 - 5.142.47.255'

% Abuse contact for '5.142.44.0 - 5.142.47.255' is 'abuse@rt.ru'

inetnum:        5.142.44.0 - 5.142.47.255
netname:        Rostelecom-NET
descr:          MVNO
descr:          PJSC "Rostelecom", North-West branch
country:        RU
admin-c:        RCR3-RIPE
tech-c:         RCR3-RIPE
status:         ASSIGNED PA
mnt-by:         AS8997-MNT
mnt-by:         Rostelecom-MNT
mnt-lower:      AS8997-MNT
mnt-domains:    AS8997-MNT
mnt-routes:     AS8997-MNT
created:        2021-10-04T11:27:36Z
last-modified:  2021-10-04T11:27:36Z
source:         RIPE

role:           ru.spbnit contact role
address:        OJSC Rostelecom
address:        191186, St.-Petersburg
address:        Russia
phone:          +7 812 595 45 56
remarks:        --------------------------------------------
admin-c:        AA728-RIPE
admin-c:        VE128-RIPE
tech-c:         AA728-RIPE
tech-c:         VE128-RIPE
tech-c:         TR4627-RIPE
tech-c:         RT8555-RIPE
nic-hdl:        RCR3-RIPE
remarks:        --------------------------------------------
remarks:        General questions: ip-noc(at)nw.rt.ru
remarks:        Routing & peering: ip-noc(at)nw.rt.ru
remarks:        --------------------------------------------
abuse-mailbox:  abuse@rt.ru
mnt-by:         AS8997-MNT
created:        2002-09-04T09:29:24Z
last-modified:  2023-04-20T16:55:52Z
source:         RIPE # Filtered

% Information related to '5.142.0.0/18AS12389'

route:          5.142.0.0/18
descr:          PJSC "Rostelecom" North-West Region
descr:          SPBNIT-RU Autonomous System
origin:         AS12389
mnt-by:         AS8997-MNT
created:        2016-11-17T10:52:18Z
last-modified:  2016-11-17T10:52:18Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.114 (BUSA)

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