% 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 '77.243.12.0 - 77.243.15.255'

% Abuse contact for '77.243.12.0 - 77.243.15.255' is 'abuse@sovtest.ru'

inetnum:        77.243.12.0 - 77.243.15.255
netname:        SOVTEST
descr:          Sovtest-Internet Limited Company: ISP in Kursk, Russia
country:        ru
admin-c:        IK103-RIPE
tech-c:         SB5337-RIPE
remarks:        INFRA-SW
status:         ASSIGNED PA
mnt-by:         SOVTEST-MNT
mnt-lower:      SOVTEST-MNT
mnt-domains:    SOVTEST-MNT
mnt-routes:     SOVTEST-MNT
created:        2008-11-10T10:23:11Z
last-modified:  2008-11-10T10:23:11Z
source:         RIPE # Filtered

person:         Igor A Kononov
address:        AOZT SovTest
address:        12, Mozhaevskaya Str.
address:        305000 Kursk
address:        Russia
remarks:        phone: +7 0712 545444
phone:          +7 4712 545444
remarks:        phone: +7 0712 545445
phone:          +7 4712 545445
remarks:        fax-no: +7 0712 563550
fax-no:         +7 4712 563550
nic-hdl:        IK103-RIPE
created:        1970-01-01T00:00:00Z
last-modified:  2015-07-03T13:37:53Z
source:         RIPE # Filtered
remarks:        modified for Russian phone area changes
mnt-by:         SOVTEST-MNT

person:         Sergey Brusov
address:        12, Mozhaevskaya Str.
address:        305000 Kursk Russia
phone:          +7 4712 730037
fax-no:         +7 4712 730038
nic-hdl:        SB5337-RIPE
created:        1970-01-01T00:00:00Z
last-modified:  2016-09-13T07:55:49Z
source:         RIPE # Filtered
mnt-by:         SOVTEST-MNT

% Information related to '77.243.0.0/20AS42516'

route:          77.243.0.0/20
descr:          Sovtest-Internet
origin:         AS42516
mnt-by:         SOVTEST-MNT
created:        2007-03-06T16:24:47Z
last-modified:  2007-03-06T16:24:47Z
source:         RIPE # Filtered

% Information related to '77.243.0.0/20AS44266'

route:          77.243.0.0/20
origin:         AS44266
descr:          Sovtest-Internet
mnt-by:         SOVTEST-MNT
created:        2023-09-05T12:18:24Z
last-modified:  2023-09-05T12:19:29Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.113.2 (SHETLAND)

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