MFOLD - Prediction of RNA secondary structure by free energy minimization. 
      - Version 2.0 : suboptimal folding with temperature dependence
      - Michael Zuker and John Jaeger 
      - LRNA : folds linear RNA sequences
      - CRNA : folds circular RNA sequences

Any research that uses these programs should cite :

   M. Zuker 
   On Finding All Suboptimal Foldings of an RNA Molecule.
   Science, 244, 48-52, (1989)

   J. A. Jaeger, D. H. Turner and M. Zuker 
   Improved Predictions of Secondary Structures for RNA.
   Proc. Natl. Acad. Sci. USA, BIOCHEMISTRY, 86, 7706-7710, (1989)

   J. A. Jaeger, D. H. Turner and M. Zuker 
   Predicting Optimal and Suboptimal Secondary Structure for RNA.
   in "Molecular Evolution: Computer Analysis of Protein and
   Nucleic Acid Sequences", R. F. Doolittle ed.
   Methods in Enzymology, 183, 281-306 (1989)