diff --git a/src/parser.rs b/src/parser.rs
index d86516a..bae9737 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -434,7 +434,7 @@ pub fn int_subset(input: &str) -> IResult<&str, IntSubset> {
 }
 
 enum MarkupDecl<'s> {
-    ElementDecl(ElementDecl<'s>),
+    Elementdecl(Elementdecl<'s>),
     AttlistDecl(AttlistDecl<'s>),
     EntityDecl(EntityDecl<'s>),
     NotationDecl(NotationDecl<'s>),
@@ -444,8 +444,8 @@ enum MarkupDecl<'s> {
 /// [29]   	markupdecl	   ::=   	elementdecl | AttlistDecl | EntityDecl | NotationDecl | PI | Comment
 pub fn markup_decl(input: &str) -> IResult<&str, MarkupDecl> {
     alt((
-        map(element_decl, |element_decl| {
-            MarkupDecl::ElementDecl(element_decl)
+        map(elementdecl, |elementdecl| {
+            MarkupDecl::Elementdecl(elementdecl)
         }),
         map(attlist_decl, |attlist_decl| {
             MarkupDecl::AttlistDecl(attlist_decl)
@@ -613,6 +613,169 @@ pub fn empty_elem_tag(input: &str) -> IResult<&str, EmptyElemTag> {
     )(input)
 }
 
+struct Elementdecl<'s> {
+    name: Name<'s>,
+    contentspec: Contentspec<'s>,
+}
+/// [45]   	elementdecl	   ::=   	'<!ELEMENT' S Name S contentspec S? '>'
+pub fn elementdecl(input: &str) -> IResult<&str, Elementdecl> {
+    map(
+        delimited(
+            pair(tag("<!ELEMENT"), s),
+            separated_pair(name, s, contentspec),
+            pair(opt(s), tag(">")),
+        ),
+        |(name, contentspec)| Elementdecl { name, contentspec },
+    )(input)
+}
+
+// TODO: casings???
+#[derive(Clone)]
+enum Contentspec<'s> {
+    Empty,
+    Any,
+    Mixed(Mixed<'s>),
+    Children(Children<'s>),
+}
+/// [46]   	contentspec	   ::=   	'EMPTY' | 'ANY' | Mixed | children
+pub fn contentspec(input: &str) -> IResult<&str, Contentspec> {
+    alt((
+        value(Contentspec::Empty, tag("EMPTY")),
+        value(Contentspec::Any, tag("ANY")),
+        map(mixed, |mixed| Contentspec::Mixed(mixed)),
+        map(children, |children| Contentspec::Children(children)),
+    ))(input)
+}
+
+#[derive(Clone)]
+enum Occurence {
+    Once,
+    Optional,
+    Many0,
+    Many1,
+}
+/// Occurence ::= ('?' | '*' | '+')?
+pub fn occurence(input: &str) -> IResult<&str, Occurence> {
+    map(
+        opt(alt((tag("?"), tag("*"), tag("+")))),
+        |occurence| match occurence {
+            Some("?") => Occurence::Optional,
+            Some("*") => Occurence::Many0,
+            Some("+") => Occurence::Many1,
+            _ => Occurence::Once,
+        },
+    )(input)
+}
+
+#[derive(Clone)]
+enum ChildrenKind<'s> {
+    Choice(Choice<'s>),
+    Seq(Seq<'s>),
+}
+#[derive(Clone)]
+struct Children<'s> {
+    kind: ChildrenKind<'s>,
+    occurence: Occurence,
+}
+/// [47]   	children	   ::=   	(choice | seq) ('?' | '*' | '+')?
+pub fn children(input: &str) -> IResult<&str, Children> {
+    map(
+        pair(
+            alt((
+                map(choice, |choice| ChildrenKind::Choice(choice)),
+                map(seq, |seq| ChildrenKind::Seq(seq)),
+            )),
+            occurence,
+        ),
+        |(kind, occurence)| Children { kind, occurence },
+    )(input)
+    // alt((
+    //     map(pair(choice, occurence), |(choice, occurence)| Children::Choice(choice, occurence)),
+    //     map(pair(seq, occurence), |(seq, occurence)| Children::Seq(seq, occurence))
+    // ))(input)
+}
+
+#[derive(Clone)]
+enum CpKind<'s> {
+    Name(Name<'s>),
+    Choice(Choice<'s>),
+    Seq(Seq<'s>),
+}
+#[derive(Clone)]
+struct Cp<'s> {
+    kind: CpKind<'s>,
+    occurence: Occurence,
+}
+/// [48]   	cp	   ::=   	(Name | choice | seq) ('?' | '*' | '+')?
+pub fn cp(input: &str) -> IResult<&str, Cp> {
+    map(
+        pair(
+            alt((
+                map(name, |name| CpKind::Name(name)),
+                map(choice, |choice| CpKind::Choice(choice)),
+                map(seq, |seq| CpKind::Seq(seq)),
+            )),
+            occurence,
+        ),
+        |(kind, occurence)| Cp { kind, occurence },
+    )(input)
+}
+
+#[derive(Clone)]
+struct Choice<'s>(Vec<Cp<'s>>);
+/// [49]   	choice	   ::=   	'(' S? cp ( S? '|' S? cp )+ S? ')'
+pub fn choice(input: &str) -> IResult<&str, Choice> {
+    map(
+        delimited(
+            pair(tag("("), opt(s)),
+            pair(cp, many1(preceded(tuple((opt(s), tag("|"), opt(s))), cp))),
+            pair(opt(s), tag(")")),
+        ),
+        |(first, rest)| {
+            let choice = vec![vec![first], rest].concat();
+            Choice(choice)
+        },
+    )(input)
+}
+
+#[derive(Clone)]
+struct Seq<'s>(Vec<Cp<'s>>);
+/// [50]   	seq	   ::=   	'(' S? cp ( S? ',' S? cp )* S? ')'
+pub fn seq(input: &str) -> IResult<&str, Seq> {
+    map(
+        delimited(
+            pair(tag("("), opt(s)),
+            pair(cp, many0(preceded(tuple((opt(s), tag(","), opt(s))), cp))),
+            pair(opt(s), tag(")")),
+        ),
+        |(first, rest)| {
+            let seq = vec![vec![first], rest].concat();
+            Seq(seq)
+        },
+    )(input)
+}
+
+// always contains #PCDATA
+#[derive(Clone)]
+struct Mixed<'s>(Vec<Name<'s>>);
+/// [51]   	Mixed	   ::=   	'(' S? '#PCDATA' (S? '|' S? Name)* S? ')*' | '(' S? '#PCDATA' S? ')'
+pub fn mixed(input: &str) -> IResult<&str, Mixed> {
+    alt((
+        map(
+            delimited(
+                tuple((tag("("), s, tag("#PCDATA"))),
+                many0(preceded(tuple((opt(s), tag("|"), opt(s))), name)),
+                pair(opt(s), tag(")*")),
+            ),
+            |names| Mixed(names),
+        ),
+        value(
+            Mixed(Vec::new()),
+            tuple((tag("("), opt(s), tag("#PCDATA"), opt(s), tag(")"))),
+        ),
+    ))(input)
+}
+
 enum CharRef<'s> {
     Decimal(&'s str),
     Hexadecimal(&'s str),