If you are (or not) happy with the Stack-Of-Tasks and want to cite it, please use the following citation:

@inproceedings {mansard:icar:09,
    title = {A Versatile Generalized Inverted Kinematics Implementation for Collaborative Working Humanoid Robots: The Stack of Tasks},
    booktitle = {International Conference on Advanced Robotics (ICAR)},
    year = {2009},
    month = {June},
    pages = {119},
    url = {http://hal-lirmm.ccsd.cnrs.fr/file/index/docid/796736/filename/2009_icar_mansard-Stack_of_Tasks.pdf},
    author = {N. Mansard and O. Stasse and P. Evrard and A. Kheddar}
}