Temperature-dependent phagotrophy and phototrophy in a mixotrophic chrysophyte by Sarah DeVaul Princiotta, Brian T. Smith and Robert W. Sanders has been published in the Journal of Phycology (52:432-440) and can be found here.

Defining planktonic protist functional groups on mechanisms for energy and nutrient acquisition: incorporation of diverse mixotrophic strategies by Aditee Mitra and 22 co-authors (including R.W. Sanders) was published in Protist (167:106-120) and is available online at  http://www.sciencedirect.com/science/article/pii/S1434461016000043