Some unscientific testing of a red filter + polarizing filter for B&W : r/AnalogCommunity
Polarizing filters test 2015 - B+W Circular-Pol E - LensTip.com
Circular Polarizer Filter Review
Amazon.com : B + W Circular Polarizer Kaesemann - Standard Mount (F-PRO), HTC, 16 Layers Multi-Resistant Coating, Photography Filter, 77 mm : Electronics
B+W 37mm XS-Pro Kaesemann High Transmission Circular Polarizer MRC Nan — Glazer's Camera Inc