The default definitions for this are in biblatex.def. In your case, they are:
\DeclareFieldFormat[article,inbook,incollection,inproceedings,patent,thesis,unpublished]{citetitle}{\mkbibquote{#1\isdot}}
\DeclareFieldFormat[article,inbook,incollection,inproceedings,patent,thesis,unpublished]{title}{\mkbibquote{#1\isdot}}
So you can add the following to your own .tex file (or to a biblatex.cfg):
\DeclareFieldFormat[inbook]{citetitle}{#1}
\DeclareFieldFormat[inbook]{title}{#1}
The first removes the quotation marks from your citations; the second from the bibliography.
\documentclass{article}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@InBook{entry1,
author = {Author, A.},
booktitle = {Main Title of Book},
title = {InBook Title without Quotation Marks},
publisher = {The Publisher},
date = 3000,
location = {CityPlace},
pages = {63--90},
}
@article{entry2,
author = {Author, A.},
title = {Title of Article},
journal = {Journal Title},
volume = {50},
number = {3},
date = 3000,
pages = {63--90},
}
\end{filecontents}
\usepackage[style=authortitle,backend=bibtex]{biblatex}
\addbibresource{\jobname.bib}
\DeclareFieldFormat[inbook]{citetitle}{#1}
\DeclareFieldFormat[inbook]{title}{#1}
\begin{document}
\cite{entry1,entry2}
\printbibliography
\end{document}
Since it looks like you're using the document class elsarticle (which, as you've discovered, already loads the natbib package), you may want to execute the following command:
\biboptions{square,sort,comma,numbers}
This method is described in more detail on pages 2 and 3 of the user guide of the elsarticle package.
The elsarticle package comes with three separate bibliography style files: elsarticle-num.bst, elsarticle-num-names.bst, and elsarticle-harv.bst. The first or second of these should give you the formatting you require. (elsarticle-harv, in contrast, is meant for authoryear-style citation callouts, which doesn't seem to be what you want.)
Note that if authoryear was meant to be one of the options passed to natbib, one would have to specify it as an option to the document class:
\documentclass[authoryear{,<other options>}]{elsarticle}
Best Answer
You can cite webpages with a code you can see below:
It is always a good thing to mention what is the date you have cited the webpage.