Add citations to triloop and tetraloop config files

Author: untergasser

src/primer3_config/tetraloop.dh

@@ -1,4 +1,8 @@
-# tetraloop bonuses for GNRA and GNAB kcal/mol*(-10)
+# Enthalpy tetraloop bonuses for GNRA and GNAB
+# values are in cal / mol
+
+# Values in this file originate from:
+# SantaLucia, Hicks, "The Thermodynamics of DNA Structural Motifs". Supplemental Material. Annu Rev Biophys Biomol Struct. 2004:33:415-40. doi: 10.1146/annurev.biophys.32.110601.141800.
 
 AAAAAT	500
 AAAACT	700

src/primer3_config/tetraloop.ds

@@ -1,4 +1,8 @@
-# VIIDE
+# Entropy tetraloop bonuses for GNRA and GNAB
+# values are in cal / mol K
+
+# Values in this file originate from:
+# SantaLucia, Hicks, "The Thermodynamics of DNA Structural Motifs". Supplemental Material. Annu Rev Biophys Biomol Struct. 2004:33:415-40. doi: 10.1146/annurev.biophys.32.110601.141800.
 
 AAAAAT	-650
 AAAACT	1610

src/primer3_config/triloop.dh

@@ -1,5 +1,8 @@
-# triloop bonus
-# Enthalpy Hairpin loop
+# Enthalpy Hairpin loop GNA triloop bonus
+# values are in cal / mol
+
+# Values in this file originate from:
+# SantaLucia, Hicks, "The Thermodynamics of DNA Structural Motifs". Supplemental Material. Annu Rev Biophys Biomol Struct. 2004:33:415-40. doi: 10.1146/annurev.biophys.32.110601.141800.
 
 AGAAT	-1500
 AGCAT	-1500

src/primer3_config/triloop.ds

@@ -1,4 +1,8 @@
-# bonuses for GNA triloops
+# Entropy Hairpin loop GNA triloop bonus
+# values are in cal / mol K
+
+# Values in this file originate from:
+# SantaLucia, Hicks, "The Thermodynamics of DNA Structural Motifs". Supplemental Material. Annu Rev Biophys Biomol Struct. 2004:33:415-40. doi: 10.1146/annurev.biophys.32.110601.141800.
 
 AGAAT	0
 AGCAT	0