Shallow impurities and excitons in MBE-grown quantum-sized semiconductor low-dimension;ll systems are studied within the fractional-dimensional space approach. We present calculations for shallow-donor states in GaAs(Ga,Al)As quantum wells and superlattices and fur excitons in GaAs- (Ga,AI)As quantum wells and symmetric-coupled double quantum wells. Effects of growth-direction applied magnetic fields are also considered. Results are shown to be in good agreement with previous variational calculations and available experimental measurements.