Solar powered refrigeration by means of an ammonia-water intermittent absorption cycle / J.P. van PaassenAbsorption refrigeration machines : theoretical and experimental assessment of the performance of aqua-ammonia absorption machines operated at marginal conditions, e.g. when powered by solar or waste heat : development of a new type of absorber / by C. KeizerVertical tubular absorbers for ammonia-salt absorption refrigeration / C.A. Infante Ferreira