• Dynamical deformations of three-dimensional Lie algebras in Bianchi classification over the harmonic oscillatorPaal, Eugen; Virkepu, JüriJournal of mathematical physics2009 / p. 053523-1 - 053523-8
• How to compose Lagrangian?Paal, Eugen; Virkepu, JüriGeneralized Lie theory in mathematics, physics and beyond2009 / p. 131-140
• Jacobi operators of quantum counterparts of three-dimensional real Lie algebras over the harmonic oscillatorPaal, Eugen; Virkepu, JüriAlgebra, geometry and mathematical physics2011 / p. 199-209
• Lie teooriastVirkepu, JüriAastaraamat 2005 / Eesti Matemaatika Selts2006 / lk. 30-51
• Note on 2d binary operadic harmonic oscillatorPaal, Eugen; Virkepu, JüriJournal of generalized Lie theory and applications2008 / 3, p. 221-225 https://www.hilarispublisher.com/open-access/note-on-d-binary-operadic-harmonic-oscillator-1736-4337-2-140.pdf
• Note on operadic harmonic oscillatorPaal, Eugen; Virkepu, JüriReports on mathematical physics2008 / 2, p. 207-212 https://www.sciencedirect.com/science/article/abs/pii/S0034487708800080
• On Lagrange formalism for Lie theory and operadic harmonic oscillator in low dimensions = Lagrange'i formalismist Lie teooriale ja harmooniline operaadostsillaator madalates dimensioonidesVirkepu, Jüri2009 https://www.ester.ee/record=b2540604*est
• Operadic quantization as a tool for discrete geometryPaal, Eugen; Virkepu, Jüri3Quantum : Algebra Geometry Information (QQQ Conference 2012) : 10-13 July 2012, Tallinn, Estonia : dedicated to memory of Professor Jean-Louis Loday (1936-2012)2014 / p. 1-9
• Operadic representations of harmonic oscillator in some 3d algebrasPaal, Eugen; Virkepu, JüriJournal of generalized Lie theory and applications2009 / 1, p. 53-59
• Plane rotations and Hamilton-Dirac mechanicsPaal, Eugen; Virkepu, JüriCzechoslovak journal of physics2005 / p. 1503-1508 https://link.springer.com/article/10.1007/s10582-006-0032-7
• Quantum counterparts of three-dimensional real Lie algebras over harmonic oscillatorPaal, Eugen; Virkepu, JüriCentral European journal of physics2009 / [7] p https://www.degruyter.com/document/doi/10.2478/s11534-009-0123-8/html?lang=en
• Quantum of VIIa, IIIa=1, VIa=/1 over the harmonic oscillator in semiclassical approximationPaal, Eugen; Virkepu, JüriProceedings of the Estonian Academy of Sciences2010 / 4, p. 347-354
• SO(2) and Hamilton-Dirac mechanicsBurdik, Cestmir; Paal, Eugen; Virkepu, JüriJournal of nonlinear mathematical physics2006 / Supplement, August, p. 37-43 https://www.tandfonline.com/doi/abs/10.2991/jnmp.2006.13.s.5
• 2D binary operadic Lax representation for harmonic oscillatorPaal, Eugen; Virkepu, JüriKoninklijke Vlaamse Academie van Belgie voor Wetenschappen en Kunsten2010 / p. 209-216 https://www.researchgate.net/publication/1913785_2D_binary_operadic_Lax_representation_for_harmonic_oscillator