1. Or, J.: Humanoids grow a spine: the effect of lateral spinal motion on the mechanical energy efficiency. IEEE Robot. Autom. Mag. 20(2), 71–81 (2013).
2. Penčić, M.M., Borovac, B.A., Kovačević, D.I., Čavić, M.V: Development of the multi-segment lumbar spine for humanoid robots. Therm. Sci. 20(suppl. 2), S581–S590 (2016).
3. Penčić, M., Rackov, M., Čavić, M., Kiss, I., Cioată, V.G.: Social humanoid robot SARA: development of the wrist mechanism. IOP Conf. Ser.: Mater. Sci. Eng. 294(1), 012079-1–012079-10 (2017).
4. Penčić, M., Čavić, M., Rackov, M., Borovac, B., Lu, Z.: Drive system of the robot eyeballs and eyelids with 8 DOFs. In: Doroftei, I., Oprisan, C., Pisla, D., Lovasz, E.-C. (eds.) New Advances in Mechanism and Machine Science: SYROM 2017, MMS, vol. 57, pp. 47–56. Springer, Cham (2018).
5. Penčić, M., Čavić, M., Borovac, B., Lu, Z., Rackov, M.: Robotic eyes with 7 DOFs: structural design and motion simulation. In: Arakelian, V., Wenger, P. (eds.) ROMANSY 22 – Robot Design, Dynamics and Control, CISM, vol. 584, pp. 52–60. Springer, Cham (2019).