Search all R packages and function manuals. Same help pages as with the ? command, presented in a nicer way. Provides more search options as well as the possibility to comment on packages etc.
R. Brumana, D. Oreni, A. Raimondi, A. Georgopoulos, and A. Bregianni. The Institute of Electrical and Electronics Engineers, Inc. (IEEE) Conference Proceedings, 1, page 497. Piscataway, The Institute of Electrical and Electronics Engineers, Inc. (IEEE), (October 2013)