Wiswesser line notation

Wiswesser line notation (WLN), invented by William J. Wiswesser in 1949,{{cite book|first1=William J.|last1=Wiswesser|title=Simplified chemical coding for automatic sorting and printing machinery|publisher=Willson Products Inc., Reading, PA|year=1951}}{{cite journal|first1=William J.|last1=Wiswesser|title=The Wiswesser line formula notation|journal=Chem. Eng. News|volume=30|pages=3525–3526|year=1952|issue=34|doi=10.1021/cen-v030n034.p3523}}{{cite journal| first1=William J.|last1=Wiswesser|title=107 years of line-formula notations (1861-1968)|journal = Journal of Chemical Documentation|volume=8|issue=3|pages=146–150|year=1968 |doi=10.1021/c160030a007}}{{cite journal|first1=William J. | last1=Wiswesser|title=How the WLN began in 1949 and how it might be in 1999|journal=J. Chem. Inf. Comput. Sci.|year=1982|volume=22|issue=2|pages=88–93|doi=10.1021/ci00034a005}}{{cite journal|first1=William J.|last1=Wiswesser | title=Historic development of chemical line notation | journal=J. Chem. Inf. Comput. Sci.|volume=25|issue=3|pages=258–263|year=1985|doi=10.1021/ci00047a023}} was the first line notation capable of precisely describing complex molecules. It was the basis of ICI Ltd's CROSSBOW database system developed in the late 1960s. WLN allowed for indexing the Chemical Structure Index (CSI) at the Institute for Scientific Information (ISI). It was also the tool used to develop the CAOCI (Commercially Available Organic Chemical Intermediates) database, the datafile from which Accelrys' (successor to MDL) ACD file was developed. WLN is still being extensively used by BARK Information Services. Descriptions of how to encode molecules as WLN have been published in several books.{{cite book|first1=William J.|last1=Wiswesser|title=A line-formula chemical notation|publisher=Thomas Y. Crowell Co., New York, NY|year=1954}}{{cite book|first1=Elbert George|last1=Smith|first2=Aaron|last2=Addelston|first3=William J.|last3=Wiswesser|title=The Wiswesser line-formula chemical notation|publisher=McGraw-Hill Book Co., New York, NY|year=1968}}{{cite book|first1=Elbert George|last1=Smith|first2=P. A.|last2=Baker|title=The Wisswesser Line-Formula Chemical Notation (WLN)|publisher=Chemical Information Management Inc., Cherry Hill, NJ|year=1975}}