# Hamiltonianos Efectivos en Resonancia Paramagnética Electrónica: aplicación a los alumbres de Cs y Ti.
# [http://www.academia.edu/attachments/12820002/download_file An effective Hamiltonian and time-independent perturbation theory].
# [https://www.academia.edu/4998601/Developpement_dun_operateur_en_termes_doperateurs_de_spin_effectif Spin effectif].# [https://www.academia.edu/4525949/Diagonalization_of_the_g-Matrix_of_Low_Symmetry_Transition_Ions Diagonalisation of the g-matrix of low symmetry transition ions].
# [https://www.academia.edu/1267029/The_Use_of_Irreducible_Operators_for_Determining_the_Complete_Set_of_Linearly_Independent_Crystal_Field_Parameters The Use of Irreducible Operators for Determining the Complete Set of Linearly Independent Crystal Field Parameters].
# [https://www.academia.edu/4525945/The_Derivation_of_Effective_Hamiltonians The main equations which define an effective Hamiltonian].
# [http://cyt-ar.com.ar/cyt-ar/images/9/95/General_Theory_of_Effective_Hamiltonians.pdf General theory of Effective Hamiltonians].
# [http://www.academia.edu/attachments/6417299/download_file Derivation of model Hamiltonians: Exchange Hamiltonian for H<sub>2</sub>].