See the paintings of Joan Mitchell here.
Read the Irving Sandler article Mitchell Paints a Picture (ArtNews 11/05/12).

Writer, historian and SJSU faculty member Patricia Albers is the author of Joan Mitchell: Lady Painter. This lecture (beginning at 6 min) was presented at the Brooklyn Museum in 2013.

The lecture below was given by curator, Timothy Anglin Burgard on Sept 7, 2013 during the De Young exhibition, Richard Diebenkorn: The Berkeley Years, 1953—1966. Titled Richard Diebenkorn: Known and Unknown, it gives a wonderful overview of Diebenkorn's work. Start at 7:00 minutes.

I also recommend this 30 minute lecture given on the same day about artists influencing other artists. Presented by curator Janet Bishop, it is titled Painters Looking at Paintings: Henri Matisse, Richard Diebenkorn, Wayne Thiebaud, and Robert Bechtle.

And here is a short clip in which Richard Diebenkorn discusses the practice of making art and the relevance of landscape.