Icosahedric triangulation number is calculated following Caspar and Klug system 
Physical principles in the construction of regular viruses
D. L. Caspar, A. Klug
Cold Spring Harb. Symp. Quant. Biol. 1962; 27: 1??24
D. L. Caspar, A. Klug
Cold Spring Harb. Symp. Quant. Biol. 1962; 27: 1??24
Insight into DNA and protein transport in double-stranded DNA viruses: the structure of bacteriophage N4
Kyung H. Choi, Jennifer McPartland, Irene Kaganman, Valorie D. Bowman, Lucia B. Rothman-Denes, Michael G. Rossmann
J. Mol. Biol. May 2, 2008; 378: 726-736
Kyung H. Choi, Jennifer McPartland, Irene Kaganman, Valorie D. Bowman, Lucia B. Rothman-Denes, Michael G. Rossmann
J. Mol. Biol. May 2, 2008; 378: 726-736
Structure of the Ty3/Gypsy retrotransposon capsid and the evolution of retroviruses
Svetlana O Dodonova, Simone Prinz, Virginia Bilanchone, Suzanne Sandmeyer, John A G Briggs
Proc Natl Acad Sci U S A. 2019 May 14;116(20):10048-10057.
Proc Natl Acad Sci U S A. 2019 May 14;116(20):10048-10057.