diff --git a/constants/null_doi.php b/constants/null_doi.php
index d13fbe4eb3..97fd15bc1e 100644
--- a/constants/null_doi.php
+++ b/constants/null_doi.php
@@ -33,6 +33,7 @@
 '10.1017/CBO9780511607141',
 '10.1017/cbo9780511610486.005',
 '10.1017/cbo9781139696562.001',
+'10.1023/A:1004047600718',
 '10.1023/A:1017936319069',
 '10.1023/A:1021366131934',
 '10.1036/0071422803',
@@ -58,6 +59,7 @@
 '10.1225/F00503',
 '10.1258/j.jmb.2005.04-49',
 '10.12788/ajo.2018.0018',
+'10.13176/11.106',
 '10.1336/0313268762',
 '10.1360/982005-575',
 '10.1379/1466-1268(2000)005<0098:mhdhco>2.0.co;2',
@@ -65,7 +67,11 @@
 '10.1379/1466-1268(2001)006<0377:GOAPAO>2.0.CO;2',
 '10.1385/1-59745-395-1:163',
 '10.1385/NMM:8:1-2:217',
+'10.1400/34421',
+'10.1400/41466',
 '10.14203/mri.v24i0.400',
+'10.14240/jmhs.v2i3.32',
+'10.14240/jmhs.v5i1.81',
 '10.14334/wartazoa.v27i4.1692',
 '10.14429/dsj.33.6188',
 '10.14429/dsj.53.2282',
@@ -104,10 +110,12 @@
 '10.17312/harringtonparkpress/2014.09.msws.010',
 '10.17402/205',
 '10.17694/bajece.06954',
+'10.17795/bhs-35330',
 '10.17851/2358-9787.26.3.75-100',
 '10.18226/21789061.v11i2p400',
 '10.18282/amor.v2.i4.58',
 '10.18520/cs/v110/i6/996-999',
+'10.18520/cs/v112/i01/52-61',
 '10.18551/issn1997-0749.2014-06',
 '10.18809/jbms.2015.0111',
 '10.18809/jbms.2016.0108',
@@ -179,6 +187,7 @@
 '10.3232/REB.2017.V4.N8.3069',
 '10.3320/1.2759009',
 '10.36076/ppj.2018.5.E573',
+'10.36251/josi.40',
 '10.3724/SP.J.1245.2011.00001',
 '10.3828/978-0-85323-106-6',
 '10.3828/978-0-85323-752-5',
@@ -236,16 +245,25 @@
 '10.1017/S0043887119000157',
 '10.1080/08912963.2016.1166360',
 '10.1080/13697130802054078',
+'10.1093/acref/9780195301731.013.45639',
 '10.1093/anb/9780198606697.article.1302612',
+'10.1093/gmo/9781561592630.article.00904',
+'10.1093/gmo/9781561592630.article.05207',
 '10.1093/gmo/9781561592630.article.29523',
+'10.1093/ref:odnb/101214',
 '10.1093/ref:odnb/12950',
 '10.1093/ref:odnb/34349',
+'10.1093/ref:odnb/34407',
 '10.1093/ref:odnb/35778',
 '10.1093/ref:odnb/37382',
+'10.1093/ref:odnb/39831',
+'10.1093/ref:odnb/4556',
 '10.1093/ref:odnb/45776',
 '10.1093/ref:odnb/49417',
+'10.1093/ref:odnb/56108',
 '10.1093/ref:odnb/610',
 '10.1093/ref:odnb/8581',
+'10.1093/ref:odnb/95151',
 '10.1097/00043426-200306000-00002',
 '10.1101/gr.082701.108',
 '10.1103/PhysRevLett.92.121101',
@@ -271,6 +289,8 @@
 '10.1130/1052-5173(2005)015[4:TSFHIO]2.0.CO;2',
 '10.1130/GSAT01701A.1',
 '10.1130/GSAT01701A.1',
+'10.1130/gsat01801gw.1',
+'10.1130/GSAT01801GW.1',
 '10.1130/GSAT01802A.1',
 '10.1130/GSAT151A.1',
 '10.1130/GSAT151A.1',
@@ -348,6 +368,8 @@
 '10.18520/cs/v112/i05/923-932',
 '10.18520/cs/v112/i05/933-940',
 '10.18520/v109/i6/1061-1069',
+'10.18820/24150509/JCH42.v1.8',
+'10.18845/tm.v28i4.2438',
 '10.18926/AMO/30942',
 '10.21504/amj.v3i1.732',
 '10.21504/amj.v5i3.1655',