We cordially invite the interested authors to contribute their original research papers as well as good expository papers to this special issue that will make better improvement on the theory of Clifford analysis and its application to mathematical physics, new approaches to differential geometry using Clifford's geometric analysis. Potential topics include but are not limited to:

• Theory of hyperholomorphic functions, regular functions, monogenic functions, hypercomplex number, dual number systems, spilt number systems, bicomplex numbers, and split biquaternions and pseudoquaternions
• Analytic extensions and applications
• General theory of complex analytic spaces
• Complex partial differential operators, quaternion matrix equations, and generalized Cauchy-Riemann systems
• Domains of hyperholomorphy
• Complex function spaces and hyperconjugate harmonic function
• Broadly, recent advances on complex analysis

Before submission authors should carefully read over the journal's Authors Guidelines, which are located at http://www.hindawi.com/journals/aaa/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/submit/journals/aaa/hyper/ according to the following timetable: