documentclass[14pt]{article}

usepackage{fancyhdr}
pagestyle{fancy}

usepackage[T1]{fontenc}
usepackage[utf8]{inputenc}
usepackage{lmodern}
usepackage{graphicx}
usepackage{textcomp}
usepackage[american,italian]{babel}
usepackage[babel,italian=guillemets]{csquotes}
usepackage{hyperref}
usepackage{ifthen}
usepackage{datetime}

usepackage[style=philosophy-modern,hyperref,defernumbers=true,annotation=true,sorting=nyvt]{biblatex}
%usepackage[style=apa,hyperref,sorting=nyvt]{biblatex}  % not better than above
addbibresource{test.bib}

begin{document}
author{myself}
title{main bib}
maketitle

noindent
nocite{*}

defbibheading{Main}{section{Main Section}}
defbibnote{A}{nice books}

newrefcontext[labelprefix={A-}]
printbibliography[heading=Main, prenote={A}, keyword=A]

end{document}

@Booklet{AAA,
author = {name surname},
label = {Ab},
title = {main title A, also as  parencite{BBB},
pag.1-99, parencite{CCC}, {parencite{DDD}}, pp. 100-199},
howpublished = {Ok},
year = {2014},
location = {MyTown},
annotation = {also as  parencite{BBB}, pag.1-99, parencite{CCC}, {parencite{DDD}}, pp. 1-99},
keywords = {A}
}

@Book{BBB,
author = {alpha beta},
title = {Main Book B},
publisher = {editor},
year = {2015},
keywords = {A}
}

@Book{CCC,
author = {aaa BBB},
title = {Main Book C},
publisher = {editor},
year = {2016},
keywords = {A}
}

@Book{DDD,
author = {{NML} {IJK}},
title = {Main Book D},
publisher = {editor},
year = {2017},
keywords = {A}
}