Hellgren, O. (1984). Acclimation to quantum flux density, temperature and photoperiod as effects on growth, development, chlorophyll content and leaf characteristics in Pelargonium zonale hybr. Swedish University of Agricultural Sciences.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHellgren, Olof. Acclimation to Quantum Flux Density, Temperature and Photoperiod as Effects on Growth, Development, Chlorophyll Content and Leaf Characteristics in Pelargonium Zonale Hybr. Alnarp: Swedish University of Agricultural Sciences, 1984.
एमएलए (8वां संस्करण) प्रशस्ति पत्रHellgren, Olof. Acclimation to Quantum Flux Density, Temperature and Photoperiod as Effects on Growth, Development, Chlorophyll Content and Leaf Characteristics in Pelargonium Zonale Hybr. Swedish University of Agricultural Sciences, 1984.