@article{Fister2013Modified,
 author = {Fister, Iztok and Yang, Xin-She and Brest, Janez, Fister Jr., Iztok},
 journal = {Expert Systems with Applications},
 number = {18},
 pages = {7220--7230},
 publisher = {Elsevier},
 title = {Modified firefly algorithm using quaternion representation},
 volume = {40},
 year = {2013}
}