Bdtyktl

If you do know, which package do I need to use? Thanks.

With the MnSymbol package, you could use the following symbols:

documentclass{article}



usepackage{MnSymbol}



begin{document}



[

rcirclerightint

lcirclerightint

rcircleleftint

lcircleleftint

]



end{document}

(other package might know these symbols as ointclockwise and ointctrclockwise)

If you only want half a circle, you can use the mathdesign package:

documentclass{article}



usepackage[charter]{mathdesign}



begin{document}



[

intclockwise

]



end{document}

documentclass{standalone}

usepackage{array,esint}

defCMD#1{%

   $ csname#1endcsname displaystylecsname#1endcsname $ & texttt{textbackslash#1} &}



begin{document}

defarraystretch{2}

begin{tabular}{@{}*{2}{r@{kern3pt}l}r@{kern3pt}l@{}l@{}}

CMD{int}   CMD{iint}     CMD{iiintop} \

CMD{iiiintop}CMD{dotsintop}CMD{ointop}  \

CMD{oiint}   CMD{sqint}    CMD{sqiint} \

CMD{ointctrclockwise} CMD{ointclockwise} CMD{varointclockwise} \

CMD{varointctrclockwise} CMD{fint} CMD{varoiint}\

CMD{landupint} CMD{landdownint}

end{tabular}

end{document}

Although some of the symbols in esint come very close, I don't believe there is any package (for pdfLaTeX) that provides a version of this symbol compatible with the computer modern maths font.

The following is a (very simple) adaption of this answer by Heiko Oberdiek.
It can be used to superimpose any symbol on top of an integral sign.

documentclass{article}



usepackage{graphicx} %% <- for resizebox and rotatebox

usepackage{amsmath}

usepackage{amssymb} %% <- for curverightarrow, curveleftarrow



makeatletter %% <- make @ usable in macro names



letDOTSIrelax % amsmath support for dots

newcommand*{letteronint}[1]{%

  DOTSI

  mathop{%

    mathpalette@LetterOnInt{#1}%

  }%

  mkern-thinmuskip % thin space is inserted between two mathop

  int

}

newcommand*{@LetterOnInt}[2]{%

  sbox0{$#1intm@th$}%

  sbox2{$%

    ifx#1displaystyle

      textstyle

    else

      scriptscriptstyle

    fi

    #2%

  m@th$}%

  dimen@=.4dimexprht0+dp0relax

  ifdimdimexprht2+dp2relax>dimen@

    sbox2{resizebox*{!}{dimen@}{unhcopy2}}%

  fi

  dimen@=wd0 %

  ifdimwd2>dimen@

    dimen@=wd2 %

  fi

  rlap{hbox to dimen@{hfil

    $#1vcenter{copy2}m@th$%

  hfil}}%

  ifdimdimen@>wd0 %

    kern.5dimexprdimen@-wd0relax

  fi

}



%% Define arrow curving downwards:

newcommand*{mathbin{curvearrowbotright}}{mathpaletterotmath@internalcurvearrowleft}

newcommand*rotmath@internal[2]{rotatebox{180}{$m@th#1#2$}}



makeatother %% <- revert @



newcommand*{intcw}{letteronint{,curvearrowright}}

newcommand*{intccw}{letteronint{,curvearrowbotright}}





begin{document}



[

  displaystyle      intcw_a^b f dots intccw_a^b f qquad

  textstyle         intcw_a^b f dots intccw_a^b f qquad

  scriptstyle       intcw_a^b f dots intccw_a^b f qquad

  scriptscriptstyle intcw_a^b f dots intccw_a^b f

]



end{document}

The scriptscriptstyle version does not look good, but you probably won't want to use this symbol at that scale.

documentclass[varwidth, preview]{standalone}

usepackage{unicode-math}



begin{document}

( intclockwise awint )

end{document}

The symbols are also in a number of legacy NFSS packages, including: fdsymbol, newpxmath, newtxmath, pxfonts, txfonts, stix and stix2. Some also support other aliases, but all have been updated to understand intclockwise and awint.

Some of these also include variants, such as intclockwiseup and smallintclockwise in stix. These are available in unicode-math as stylistic variants in some math fonts.

See “The Comptehensive LaTeX Symbol List” and “Every symbol (most symbols) defined by
unicode-math.”