Polymorphism of racemic imidazol-1yl succinic acid derivatives. Suitable probes for extracellular pH by magnetic resonance spectroscopic imaging (MRSI). - Paloma Ballesteros; Carmen Ubide-Barreda; Mª Luisa Rojas; Pedro José Martínez de Paz; Valeria Righi (ARKIVOC, 2011)