diff --git a/labs/lab01DbSystemPrepare.pdf b/labs/lab01DbSystemPrepare.pdf deleted file mode 100644 index 909acbb..0000000 Binary files a/labs/lab01DbSystemPrepare.pdf and /dev/null differ diff --git a/labs/lab03DbSystemBasicSQLII.pdf b/labs/lab03DbSystemBasicSQLII.pdf deleted file mode 100644 index aa90dc8..0000000 Binary files a/labs/lab03DbSystemBasicSQLII.pdf and /dev/null differ diff --git a/labs/lab09fs2db2middle.pdf b/labs/lab09fs2db2middle.pdf deleted file mode 100644 index 07ce62e..0000000 Binary files a/labs/lab09fs2db2middle.pdf and /dev/null differ diff --git a/lecture00DbSystemLabEnvForMysql.pdf b/lecture00DbSystemLabEnvForMysql.pdf deleted file mode 100644 index a89680d..0000000 Binary files a/lecture00DbSystemLabEnvForMysql.pdf and /dev/null differ diff --git a/papers/dbtextbook.pdf b/papers/dbtextbook.pdf new file mode 100644 index 0000000..f021fca Binary files /dev/null and b/papers/dbtextbook.pdf differ