diff --git a/src/albersequal.cpp b/src/albersequal.cpp
index d471b4ff..0da046fa 100644
--- a/src/albersequal.cpp
+++ b/src/albersequal.cpp
@@ -1,3 +1,46 @@
+/*
+ * Based on libgeotrans with the following Source Code Disclaimer:
+
+1. The GEOTRANS source code ("the software") is provided free of charge by
+the National Imagery and Mapping Agency (NIMA) of the United States
+Department of Defense. Although NIMA makes no copyright claim under Title 17
+U.S.C., NIMA claims copyrights in the source code under other legal regimes.
+NIMA hereby grants to each user of the software a license to use and
+distribute the software, and develop derivative works.
+
+2. Warranty Disclaimer: The software was developed to meet only the internal
+requirements of the U.S. National Imagery and Mapping Agency. The software
+is provided "as is," and no warranty, express or implied, including but not
+limited to the implied warranties of merchantability and fitness for
+particular purpose or arising by statute or otherwise in law or from a
+course of dealing or usage in trade, is made by NIMA as to the accuracy and
+functioning of the software.
+
+3. NIMA and its personnel are not required to provide technical support or
+general assistance with respect to the software.
+
+4. Neither NIMA nor its personnel will be liable for any claims, losses, or
+damages arising from or connected with the use of the software. The user
+agrees to hold harmless the United States National Imagery and Mapping
+Agency. The user's sole and exclusive remedy is to stop using the software.
+
+5. NIMA requests that products developed using the software credit the
+source of the software with the following statement, "The product was
+developed using GEOTRANS, a product of the National Imagery and Mapping
+Agency and U.S. Army Engineering Research and Development Center."
+
+6. For any products developed using the software, NIMA requires a disclaimer
+that use of the software does not indicate endorsement or approval of the
+product by the Secretary of Defense or the National Imagery and Mapping
+Agency. Pursuant to the United States Code, 10 U.S.C. Sec. 2797, the name of
+the National Imagery and Mapping Agency, the initials "NIMA", the seal of
+the National Imagery and Mapping Agency, or any colorable imitation thereof
+shall not be used to imply approval, endorsement, or authorization of a
+product without prior written permission from United States Secretary of
+Defense.
+
+*/
+
 #include "ellipsoid.h"
 #include "rd.h"
 #include "albersequal.h"
diff --git a/src/transversemercator.cpp b/src/transversemercator.cpp
index ad335d28..98ccb5c3 100644
--- a/src/transversemercator.cpp
+++ b/src/transversemercator.cpp
@@ -1,3 +1,46 @@
+/*
+ * Based on libgeotrans with the following Source Code Disclaimer:
+
+1. The GEOTRANS source code ("the software") is provided free of charge by
+the National Imagery and Mapping Agency (NIMA) of the United States
+Department of Defense. Although NIMA makes no copyright claim under Title 17
+U.S.C., NIMA claims copyrights in the source code under other legal regimes.
+NIMA hereby grants to each user of the software a license to use and
+distribute the software, and develop derivative works.
+
+2. Warranty Disclaimer: The software was developed to meet only the internal
+requirements of the U.S. National Imagery and Mapping Agency. The software
+is provided "as is," and no warranty, express or implied, including but not
+limited to the implied warranties of merchantability and fitness for
+particular purpose or arising by statute or otherwise in law or from a
+course of dealing or usage in trade, is made by NIMA as to the accuracy and
+functioning of the software.
+
+3. NIMA and its personnel are not required to provide technical support or
+general assistance with respect to the software.
+
+4. Neither NIMA nor its personnel will be liable for any claims, losses, or
+damages arising from or connected with the use of the software. The user
+agrees to hold harmless the United States National Imagery and Mapping
+Agency. The user's sole and exclusive remedy is to stop using the software.
+
+5. NIMA requests that products developed using the software credit the
+source of the software with the following statement, "The product was
+developed using GEOTRANS, a product of the National Imagery and Mapping
+Agency and U.S. Army Engineering Research and Development Center."
+
+6. For any products developed using the software, NIMA requires a disclaimer
+that use of the software does not indicate endorsement or approval of the
+product by the Secretary of Defense or the National Imagery and Mapping
+Agency. Pursuant to the United States Code, 10 U.S.C. Sec. 2797, the name of
+the National Imagery and Mapping Agency, the initials "NIMA", the seal of
+the National Imagery and Mapping Agency, or any colorable imitation thereof
+shall not be used to imply approval, endorsement, or authorization of a
+product without prior written permission from United States Secretary of
+Defense.
+
+*/
+
 #include <cmath>
 #include "rd.h"
 #include "ellipsoid.h"