SQL for cross dependent table creation

Question

How do I run this SQL script to create these tables wiwth criss-cross relation ? kinda chicken-n-egg situation.
Note : Writer<->Book
CREATE TABLE library.Writer(
name VARCHAR2(50) NOT NULL ,
CONSTRAINT Writer_name PRIMARY KEY (name) ENABLE ,
books VARCHAR2(50),
CONSTRAINT books_Writer_Book FOREIGN KEY (books) REFERENCES library.Book (title) ENABLE
CREATE TABLE library.Book(
title VARCHAR2(50) NOT NULL ,
CONSTRAINT Book_title PRIMARY KEY (title) ENABLE ,
pages NUMBER NOT NULL ,
category VARCHAR2(50) DEFAULT 'Mystery' NOT NULL ,
author VARCHAR2(50),
CONSTRAINT author_Book_Writer FOREIGN KEY (author) REFERENCES library.Writer (name) ENABLE
CREATE TABLE library.Library(
name VARCHAR2(50) NOT NULL ,
CONSTRAINT Library_name PRIMARY KEY (name) ENABLE ,
books VARCHAR2(50),
CONSTRAINT books_Library_Book FOREIGN KEY (books) REFERENCES library.Book (title) ENABLE ,
writers VARCHAR2(50),
CONSTRAINT writers_Library_Writer FOREIGN KEY (writers) REFERENCES library.Writer (name) ENABLE
);

Answer 1

While I agree with the comments for this particular schema, if your question is meant to be more general, "How do I create constraints against interdependent tables?" then you need to create the constraints using an alter table statement after creating the tables and PKs. Something like:
CREATE TABLE library.writer(
   name  VARCHAR2(50) NOT NULL,
   books VARCHAR2(50),
   CONSTRAINT writer_name PRIMARY KEY (name));
CREATE TABLE library.book(
   title    VARCHAR2(50) NOT NULL,
   pages    NUMBER NOT NULL,
   category VARCHAR2(50) DEFAULT 'Mystery' NOT NULL,
   author   VARCHAR2(50),
   CONSTRAINT book_title PRIMARY KEY (title));
CREATE TABLE library.library(
   name    VARCHAR2(50) NOT NULL,
   books   VARCHAR2(50),
   writers VARCHAR2(50),
   CONSTRAINT Library_name PRIMARY KEY (name));
ALTER TABLE writer ADD CONSTRAINT books_Writer_Book FOREIGN KEY (books)
   REFERENCES library.Book (title);
ALTER TABLE book ADD CONSTRAINT author_Book_Writer FOREIGN KEY (author)
   REFERENCES library.Writer (name);
ALTER TABLE library ADD CONSTRAINT books_Library_Book FOREIGN KEY (books)
   REFERENCES library.Book (title);
ALTER TABLE library ADD CONSTRAINT writers_Library_Writer FOREIGN KEY (writers)
   REFERENCES library.Writer (name);HTH
John