Khoa D. Nguyen Lars K. Rasmussen Albert Guillen i Fabregas Nick Letzepis MIMO ARQ Systems with multi-Level feedback. 254-258 2009 ISIT https://doi.org/10.1109/ISIT.2009.5206027 https://www.wikidata.org/entity/Q63957458 conf/isit/2009 db/conf/isit/isit2009.html#NguyenRFL09