- Impurities in triangular lattice spin 1/2 antiferromagnet, Karol Gregor and Olexei I Motrunich, cond-mat/0805.1393

- Studies of non-magnetic impurities in spin-1/2 Kagome antiferromagnet, Karol Gregor and Olexei I. Motrunich, cond-mat/0802.0299

- Spin solid phases of spin 1 and spin 3/2 antiferromagnets on a cubic lattice, Karol Gregor and Olexei I. Motrunich, Phys. Rev. B 76, 174404 (2007)

- Spin-nematic order in the frustrated pyrochlore-lattice quantum rotor model, Karol Gregor, David A. Huse and Shivaji L. Sondhi, Phys. Rev. B 74, 024425 (2006)

- Dipolar Spin Correlations in Classical Pyrochlore Magnets, Sergei V. Isakov, Karol Gregor, Roderich Moessner and Shivaji L. Sondhi, Phys. Rev. Lett. 93, 167204 (2004)