reciprocity
101Duality (projective geometry) — A striking feature of projective planes is the symmetry of the roles played by points and lines in the definitions and theorems, and (plane) duality is the formalization of this metamathematical concept. There are two approaches to the subject of …
102Measurement microphone calibration — In order to take a scientific measurement with a microphone, its precise sensitivity must be known (in volts per Pascal). Since this may change over the lifetime of the device, it is necessary to regularly calibrate measurement microphones. This… …
103Legendre symbol — The Legendre symbol or quadratic character is a function introduced by Adrien Marie Legendre in 1798 [A. M. Legendre Essai sur la theorie des nombres Paris 1798, p 186] during his partly successful attempt to prove the law of quadratic… …
104Admission to the bar in the United States — For information on individual state bars, see state bar association. Legal education in the United States …
105ethics — /eth iks/, n.pl. 1. (used with a sing. or pl. v.) a system of moral principles: the ethics of a culture. 2. the rules of conduct recognized in respect to a particular class of human actions or a particular group, culture, etc.: medical ethics;… …
106Class field theory — In mathematics, class field theory is a major branch of algebraic number theory that studies abelian extensions of number fields. Most of the central results in this area were proved in the period between 1900 and 1950. The theory takes its name… …
107British passport — British passports may be issued to people holding any of the various forms of British nationality. The British monarch does not have a passport as British passports are issued in the monarch s name [http://www.royal.gov.uk/output/page4871.asp]… …
108Efficiency wages — In labor economics, the efficiency wage hypothesis argues that wages, at least in some markets, are determined by more than simply supply and demand. Specifically, it points to the incentive for managers to pay their employees more than the… …
109Right of foreigners to vote — Suffrage, the right to vote in a particular country, generally derives from citizenship. In most countries, the right to vote is reserved to those who possess the citizenship of the country in question. Some countries, however, have extended… …
110international trade — Introduction economic transactions that are made between countries. Among the items commonly traded are consumer goods, such as television sets and clothing; capital goods, such as machinery; and raw materials and food. Other transactions… …
