% 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 '145.140.0.0 - 145.140.255.255'

% Abuse contact for '145.140.0.0 - 145.140.255.255' is 'cert@surfcert.nl'

inetnum:        145.140.0.0 - 145.140.255.255
netname:        SIVON-NET
country:        NL
admin-c:        KB467-RIPE
tech-c:         KB467-RIPE
status:         LEGACY
mnt-by:         SN-LIR-MNT
mnt-by:         SURF-AUTO-MNT
created:        2025-02-05T13:11:46Z
last-modified:  2025-10-02T17:29:25Z
source:         RIPE

role:           Stichting Kennisnet
address:        The Netherlands
admin-c:        DL68-RIPE
tech-c:         RK4064-RIPE
tech-c:         BvdH2-RIPE
tech-c:         JK4965-RIPE
nic-hdl:        KB467-RIPE
remarks:
mnt-by:         SN-LIR-MNT
created:        2007-01-05T10:33:10Z
last-modified:  2022-11-21T10:24:47Z
source:         RIPE # Filtered

% Information related to '145.140.0.0/14AS1103'

route:          145.140.0.0/14
descr:          SURFnet CIDR Block II b-c
origin:         AS1103
mnt-lower:      AS1103-MNT
mnt-routes:     AS1103-MNT
mnt-by:         AS1103-MNT
created:        2020-04-09T13:25:02Z
last-modified:  2020-04-09T13:25:02Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.120 (SHETLAND)