% APNIC found the following authoritative answer from: whois.arin.net

#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/resources/registry/whois/tou/
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
#
# Copyright 1997-2024, American Registry for Internet Numbers, Ltd.
#

NetRange:       165.20.0.0 - 165.20.255.255
CIDR:           165.20.0.0/16
NetName:        NMH
NetHandle:      NET-165-20-0-0-1
Parent:         NET165 (NET-165-0-0-0-0)
NetType:        Direct Allocation
OriginAS:       
Organization:   Northwestern Memorial Hospital (NMH-1)
RegDate:        1993-03-31
Updated:        2021-12-14
Ref:            https://rdap.arin.net/registry/ip/165.20.0.0

OrgName:        Northwestern Memorial Hospital
OrgId:          NMH-1
Address:        259 East Erie Street
City:           Chicago
StateProv:      IL
PostalCode:     60611
Country:        US
RegDate:        1993-03-31
Updated:        2024-03-19
Ref:            https://rdap.arin.net/registry/entity/NMH-1

OrgAbuseHandle: BROWJ2-ARIN
OrgAbuseName:   Brow, John 
OrgAbusePhone:  +1-312-695-2244 
OrgAbuseEmail:  jbrow@nm.org
OrgAbuseRef:    https://rdap.arin.net/registry/entity/BROWJ2-ARIN

OrgDNSHandle: JOHNS4388-ARIN
OrgDNSName:   Johnson, Terrance 
OrgDNSPhone:  +1-312-926-5875 
OrgDNSEmail:  tmjohnso@nm.org
OrgDNSRef:    https://rdap.arin.net/registry/entity/JOHNS4388-ARIN

OrgTechHandle: BROWJ2-ARIN
OrgTechName:   Brow, John 
OrgTechPhone:  +1-312-695-2244 
OrgTechEmail:  jbrow@nm.org
OrgTechRef:    https://rdap.arin.net/registry/entity/BROWJ2-ARIN

OrgDNSHandle: BROWJ2-ARIN
OrgDNSName:   Brow, John 
OrgDNSPhone:  +1-312-695-2244 
OrgDNSEmail:  jbrow@nm.org
OrgDNSRef:    https://rdap.arin.net/registry/entity/BROWJ2-ARIN

OrgAbuseHandle: JOHNS4388-ARIN
OrgAbuseName:   Johnson, Terrance 
OrgAbusePhone:  +1-312-926-5875 
OrgAbuseEmail:  tmjohnso@nm.org
OrgAbuseRef:    https://rdap.arin.net/registry/entity/JOHNS4388-ARIN

OrgTechHandle: JOHNS4388-ARIN
OrgTechName:   Johnson, Terrance 
OrgTechPhone:  +1-312-926-5875 
OrgTechEmail:  tmjohnso@nm.org
OrgTechRef:    https://rdap.arin.net/registry/entity/JOHNS4388-ARIN

RTechHandle: SYSAD36-ARIN
RTechName:   sysadmin
RTechPhone:  +1-312-926-4357 
RTechEmail:  sysadmin2@nmh.org
RTechRef:    https://rdap.arin.net/registry/entity/SYSAD36-ARIN

#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/resources/registry/whois/tou/
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
#
# Copyright 1997-2024, American Registry for Internet Numbers, Ltd.
#

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