diff --git a/MTO/Algorithms/Multi-task/Multi-population/MTES-KG/MTES_KG.m b/MTO/Algorithms/Multi-task/Multi-population/MTES-KG/MTES_KG.m
index 75b44157..ee21b55a 100644
--- a/MTO/Algorithms/Multi-task/Multi-population/MTES-KG/MTES_KG.m
+++ b/MTO/Algorithms/Multi-task/Multi-population/MTES-KG/MTES_KG.m
@@ -7,6 +7,7 @@
 %   author   = {Li, Yanchi and Gong, Wenyin and Li, Shuijia},
 %   journal  = {IEEE Transactions on Evolutionary Computation},
 %   year     = {2023},
+%   doi      = {10.1109 / TEVC.2023.3330265},
 % }
 %--------------------------------------------------------------------------
 
diff --git a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO1.m b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO1.m
index 29960099..ac203b88 100644
--- a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO1.m	
+++ b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO1.m	
@@ -9,6 +9,7 @@
 %   author   = {Li, Yanchi and Gong, Wenyin and Li, Shuijia},
 %   journal  = {IEEE Transactions on Evolutionary Computation},
 %   year     = {2023},
+%   doi      = {10.1109 / TEVC.2023.3330265},
 % }
 %--------------------------------------------------------------------------
 
diff --git a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO2.m b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO2.m
index 645b7050..acb7c678 100644
--- a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO2.m	
+++ b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO2.m	
@@ -9,6 +9,7 @@
 %   author   = {Li, Yanchi and Gong, Wenyin and Li, Shuijia},
 %   journal  = {IEEE Transactions on Evolutionary Computation},
 %   year     = {2023},
+%   doi      = {10.1109 / TEVC.2023.3330265},
 % }
 %--------------------------------------------------------------------------
 
diff --git a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO3.m b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO3.m
index a4212a0b..98402c8a 100644
--- a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO3.m	
+++ b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO3.m	
@@ -9,6 +9,7 @@
 %   author   = {Li, Yanchi and Gong, Wenyin and Li, Shuijia},
 %   journal  = {IEEE Transactions on Evolutionary Computation},
 %   year     = {2023},
+%   doi      = {10.1109 / TEVC.2023.3330265},
 % }
 %--------------------------------------------------------------------------
 
diff --git a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO4.m b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO4.m
index 3ae5d46f..b3f7f72a 100644
--- a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO4.m	
+++ b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO4.m	
@@ -9,6 +9,7 @@
 %   author   = {Li, Yanchi and Gong, Wenyin and Li, Shuijia},
 %   journal  = {IEEE Transactions on Evolutionary Computation},
 %   year     = {2023},
+%   doi      = {10.1109 / TEVC.2023.3330265},
 % }
 %--------------------------------------------------------------------------
 
diff --git a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO5.m b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO5.m
index 922235fd..148e5ecb 100644
--- a/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO5.m	
+++ b/MTO/Problems/Real-world Applications/Optimal Power Flow/OPF_MTSO5.m	
@@ -9,6 +9,7 @@
 %   author   = {Li, Yanchi and Gong, Wenyin and Li, Shuijia},
 %   journal  = {IEEE Transactions on Evolutionary Computation},
 %   year     = {2023},
+%   doi      = {10.1109 / TEVC.2023.3330265},
 % }
 %--------------------------------------------------------------------------