1. Aitken-Christie J, Parkes BD (1996) Improved embryogenesis process for initiation and maturation. International application under the Patent Cooperation Treaty (PCT). WO 96/37096. International publication date: 28 Nov 1996
2. Aronen TS, Krajnakova J, Haggman HM, Ryynanen LA (1999) Genetic fidelity of cryopreserved embryogenic cultures of open-pollinated Abies cephalonica. Plant Sci 142:163–172
3. Aurich C, Rupps A, Zoglauer K (2014) Embryo maturation ability is subjected to line ageing—a way to assure the quality of somatic embryos of Nordmann fir. In: Park YS, Bonga JM (eds) Proceedings of the 3rd international conference of the IUFRO unit 2.09.02 on Woody plant production integrating genetic and vegetative propagation technologies, Vitoria-Gasteiz, Spain, 8–12 Sept 2014, pp 127–128. Published online: www.iufro.org/download/file/18208/5477/20902-vitoria-gasteiz14-proceedings_pdf . Accessed 5 Jan 2017
4. Breton D, Harvengt L, Trontin JF, Bouvet A, Favre JM (2006) Long-term subculture randomly affects morphology and subsequent maturation of early somatic embryos in maritime pine Plant Cell. Tissue Organ Cult 87:95–108
5. De Silva V, Bostwick D, Burns KL, Oldham CD, Skryabina A, Sullards MC, Wu D, Zhang Y, May SW, Pullman GS (2008) Isolation and characterization of a molecule stimulatory to growth of early-stage somatic embryos from early-stage female gametophyte tissue of loblolly pine. Plant Cell Rep 27:633–646