@ARTICLE{DasMarVic_j2009, author = {J{\"u}rgen~Dassow and Gema~M.~Mart\'{i}n and Francisco~J.~Vico}, title = {Some Operations Preserving Primitivity of Words}, journal = tcs, year = 2009, volume = {410}, number = {30--32}, pages = {2910--2919}, url = {http://dx.doi.org/10.1016/j.tcs.2009.01.024} }