% 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 '81.19.73.0 - 81.19.73.255'

% Abuse contact for '81.19.73.0 - 81.19.73.255' is 'abuse@rambler-co.ru'

inetnum:        81.19.73.0 - 81.19.73.255
netname:        RAMBLERBO
descr:          Rambler Office
country:        RU
admin-c:        RAMB-RIPE
tech-c:         RAMB-RIPE
status:         ASSIGNED PA
mnt-by:         RAMBLER-MNT
created:        2015-07-21T14:01:48Z
last-modified:  2015-07-21T14:01:48Z
source:         RIPE # Filtered

role:           Rambler Internet Holding NOC
address:        Rambler Internet Holding LLC
address:        Varshavskoe Highway, 9 building 1
address:        Moscow, RU
phone:          +7 495 785-1700 ext. 2237
phone:          +7 495 785-0012
fax-no:         +7 495 785-1701
remarks:        ----------------------------------------------
remarks:        NOC working hours:
remarks:        10am-7pm MSK (GMT+4) work days
remarks:        ----------------------------------------------
remarks:        Contact addresses by category:
remarks:        Routing and Peering issues: noc@rambler-co.ru
remarks:        SPAM and Security issues: abuse@rambler-co.ru
remarks:        Mail issues: postmaster@rambler-co.ru
remarks:        ----------------------------------------------
abuse-mailbox:  abuse@rambler-co.ru
admin-c:        VP2246-RIPE
tech-c:         YRYS-RIPE
tech-c:         AIS616-RIPE
tech-c:         MOOR-RIPE
nic-hdl:        RAMB-RIPE
mnt-by:         RAMBLER-MNT
created:        2007-02-28T13:10:03Z
last-modified:  2023-06-29T21:50:03Z
source:         RIPE # Filtered

% Information related to '81.19.73.0/24AS24638'

route:          81.19.73.0/24
descr:          RAMBLER-81-19-73
origin:         AS24638
mnt-lower:      RAMBLER-MNT
mnt-routes:     RAMBLER-MNT
mnt-by:         RAMBLER-MNT
created:        2016-10-07T11:24:43Z
last-modified:  2016-10-07T11:24:43Z
source:         RIPE # Filtered

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

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