I follow the canonical model distributed by abntex2 and I'm having problems in reference, whenever I go to make a quote does not appear in the text and when it appears it's just the symbol @ or?.
I use the \ cite {} command and the reference does not always appear when I compile and use \ citealp * {} works, but in the text an @ appears. Below is the structure I'm using.
\ documentclass [
12pt,
openright,
twoside,
a4paper,
english,
brazil
]{abntex2}
\ usepackage {lmodern}
\ usepackage [T1] {fontenc}
\ usepackage [utf8] {inputenc}
\ usepackage {lastpage}
\ usepackage {indentfirst}
\ usepackage {color}
\ usepackage {graphicx}
\ usepackage {microtype}
\ usepackage {amsmath}
\ usepackage {mathrsfs}
\ usepackage {amsfonts}
\ usepackage {amssymb}
\ usepackage {amsthm}
\ usepackage [] {setspace}
\ usepackage {float}
\ usepackage {enumerate}
\ usepackage {graphicx}
\ usepackage {natbib}
\ usepackage {url}
\ usepackage {cite}
\ newtheorem {theo} {Theorem} [section]
\ newtheorem {define} {Definition} [section]
\ newtheorem {color} {Corollary} [section]
\ newtheorem {leo} {Motto} [section]
\ newtheorem {axiom} {Axiom}
\ newtheorem {prop} {Proposition} [section]
\ usepackage [brazilian, hyperpageref] {backref}
\ usepackage [alf] {abntex2cite}
\ renewcommand {\ backrefpagesname} {Cited on page (s): ~}
\ renewcommand {\ backref} {}
\ renewcommand * {\ backrefalt} [4] { \ ifcase # 1% No citations in the text. or Cited on page # 2. \ else Quoted # 1 times on pages # 2. \ fi}%
\ begin {document}
\ chapter {Introduction}
\ chapter {Chapter}
\ chaptet {Conclusion}
\ bibliography {reference}
\ end {document}