Light variations of massive stars (alpha Cyg variables). XVIII. The B[e] supergiants S 18 in the SMC and R 66 = HDE 268835 and R 126 = HD 37974 in the LMC

We discuss photometric monitoring (VBLUW system) of three B[e] supergiants. All three objects appear to be variable. They are subject to two (R 66 and R 126 in the LMC) and three (S 18 in the SMC) types of light oscillations which range from a few days to years, and are probably due to pulsations. We argue that a classification as alpha Cyg variables is justified. Their classification as mixed B[e]/S Dor variables is less certain, though not impossible. Also based on other cases, a strong B[e]-S Dor variable connection seems to be present. Based on observations obtained at the European Southern Observatory at La Silla, Chile.