Writing a PhD thesis is like climbing a high mountain in unknown terrain. There are many ups and downs on the way to the summit, and sometimes you think you will never reach it, especially if the summit is temporarily out of sight because you have somehow lost the orientation in the vast amount of academic literature and related problems. The best method to reach the summit was not to look at it permanently, but only to watch your steps on the way to the next peak, like a conference paper or a journal article. In the end, if you have to put things together and to prove that your initial idea did not lead into no man’s land, but did help you to discover some new route in the “terra icognita” of the scientific landscape, the air will be very thin. The last meters are in particular so exhausting that you hardly can enjoy the view from above when you have finally reached the summit.

—— Schwind M. Dynamic Pricing and Automated Resource Allocation for Complex Information Services: Reinforcement Learning and Combinatorial Auctions[M]. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg, 2007.