The Donchian channel is an indicator used in market trading developed by Richard Donchian.
 It is formed by taking the highest high and the lowest low of the last "n" periods.
 The area between the high and the low is the channel for the period chosen.
The Chief Justice of the Common Pleas was the head of the Court of Common Pleas, also known as the Common Bench or Common Place, which was the second-highest common law court in the English legal system until 1875, when it, along with the other two common law courts and the equity and probate courts, became part of the High Court of Justice.
 As such, the Chief Justice of the Common Pleas was one of the highest judicial officials in England, behind only the Lord High Chancellor and the Lord Chief Justice of England, who headed the Queen's Bench (King's when the monarch was male).
South Africa has a 'hybrid' or 'mixed' legal system, formed by the interweaving of a number of distinct legal traditions: a civil law system inherited from the Dutch, a common law system inherited from the British, and a customary law system inherited from indigenous Africans (often termed African Customary Law, of which there are many variations depending on the tribal origin).
 These traditions have had a complex interrelationship, with the English influence most apparent in procedural aspects of the legal system and methods of adjudication, and the Roman-Dutch influence most visible in its substantive private law.
 As a general rule, South Africa follows English law in both criminal and civil procedure, company law, constitutional law and the law of evidence; while Roman-Dutch common law is followed in the South African contract law, law of delict (tort), law of persons, law of things, family law, etc.
 With the commencement in 1994 of the interim Constitution, and in 1997 its replacement, the final Constitution, another strand has been added to this weave.
System of a Down, sometimes shortened to System and abbreviated as SOAD, is an Armenian-American heavy metal band from Glendale, California, formed in 1994.
 The band currently consists of Serj Tankian (lead vocals, keyboards), Daron Malakian (vocals, guitar), Shavo Odadjian (bass, backing vocals) and John Dolmayan (drums).
Deeds registration is a land management system whereby all important instruments which relate to the common law title to parcels of land are registered on a government-maintained register.
 Deeds registration systems were set up to facilitate the transfer of title.
 The system had been used in some common law jurisdictions and continues to be used in some jurisdictions, including most of the United States.
 It is being replaced by Torrens systems in many jurisdictions.
 Australia, Ireland, Hong Kong as well as most Canadian provinces have converted from Deeds registries to Torrens titles.
 Some Canadian provinces have never operated a Deeds registry and have always used Torrens titles.
 Other Canadian provinces which have converted from a Deeds registry to Torrens titles have operated both systems in conjunction until the Torrens system gradually superseded the Deeds registry system, as was the case in Nova Scotia and New Brunswick during the 2000s.
 In the Canadian province of Ontario, electronic registration led to Ontario's version of Torrens title covering almost all land, but the past deeds registration still governs some issues.
 The Canadian provinces of Quebec, Newfoundland and Labrador and Prince Edward Island are the only provinces left which still operate a Deeds registration system.
A graphene spray gun is a kinetic spray system that deposits, through supersonic acceleration, a one atom thick sheet of pure carbon named graphene by means of a de Laval nozzle, a pinched tube with an hourglass type shape.
 The system deposits graphene flakes and a hexagonal graphene lattice is created upon impact of the desired surface.
 The graphene spray gun would be utilized onto large-scale applications such as circuits, radio transmitters, and optical electronics due to the grapehene’s transparency and its remarkable conductivity of electricity.
 The supersonic spray system was first developed in May 2014 by University of Illinois professor Alexander Yarin, and Korea University professor Sam Yoon.
 Yarin went to Yoon when he learned about his work regarding kinetic spray deposition systems.
 Yarin believed that graphene could be applied to the system in order to create a layer of the material.
 After conducting experiments with the newly created system, they concluded that the graphene spray system was a success.
 The spray gun is still in its early stages of development, but is considered by many scientists and researchers to be the solution of various predicaments that occur when applying graphene onto large-scale products.
 The most common problem that would transpire within the other methods is that the layer would be uneven and coated by aggregations.
 The energy delivered by the supersonic spraying stretches the graphene evenly upon impact, and is the main reason for the spray system’s lack of defects that are common within other graphene deposition methods.
Richard Davoud Donchian (born September 1905, Hartford, Connecticut – d. 1993) was an Armenian-American commodities and futures trader, and pioneer in the field of managed futures.
The Red River system is a network of rivers surrounding the main river - Red River in North Vietnam.
 These branches of the system contribute to or receive water from Red River.
 Red River system, joining with the Thái Bình river system in the northeast, creates the Red River Delta - the second largest delta in Vietnam.
 Because of the close relation between Red River system and Thái Bình river system, the two system are known as the common name "Red and Thai Binh rivers system".
 Alluvium of the Red River system creates the central and south Red River Delta.
 Two banks of the rivers are protected by a great dyke system.
Common Era or Current Era (CE) is a year-numbering system (calendar era) for the Julian and Gregorian calendars that refers to the years since the start of this era, that is, the years beginning with AD 1.
 The preceding era is referred to as before the Common or Current Era (BCE).
 The Current Era notation system can be used as an alternative to the Dionysian era system, which distinguishes eras as AD ("anno Domini ", "[the] year of [the] Lord") and BC ("before Christ").
 The two notation systems are numerically equivalent; thus "2017 CE" corresponds to "AD 2017 " and "400 BCE" corresponds to "400 BC".
 The year-numbering system for the Gregorian calendar is the most widespread civil calendar system used in the world today.
 For decades, it has been the global standard, recognized by international institutions such as the United Nations and the Universal Postal Union.
An inquisitorial system is a legal system where the court or a part of the court is actively involved in investigating the facts of the case, as opposed to an adversarial system where the role of the court is primarily that of an impartial referee between the prosecution and the defense.
 Inquisitorial systems are used primarily in countries with civil legal systems as opposed to common law systems.
 Countries using common law, including the United States, may use an inquisitorial system for summary hearings in the case of misdemeanors such as minor traffic violations.
 The distinction between an adversarial and inquisitorial system is theoretically unrelated to the distinction between a civil legal and common law system.
 Some legal scholars consider "inquisitorial" misleading, and prefer the word nonadversarial.
 The function is often vested in the office of the public procurator, as in Russia, China, Japan, Germany, and Scotland.

Question: What do System of a Down and Richard Donchian have in common? 
Answer: Armenian-American