arXiv:1206.4565 [astro-ph.SR]AbstractReferencesReviewsResources Classifications Subjects Themes Keywords variable stars, ab-type rr lyrae star, hybrid oosterhoff i/ii system, cerro tololo inter-american observatory, galactic globular cluster m28 Tags journal article Journal Information Publisher Journal Year Month Volume Number Pages DOI URL Miscellaneous Typesetting Pages Language License Submit Reset