Sp.js Is not loading in Application pages

Question

Unable to get property 'get_current' of undefined or null reference  is getting while running application page.
<asp:Content ID="PageHead" ContentPlaceHolderID="PlaceHolderAdditionalPageHead" runat="server">
<SharePoint:ScriptLink ID="ScriptLink2" Name="SP.js" runat="server" OnDemand="true" Localizable="false" />
<script type="text/javascript" src="/_layouts/15/1033/TCSU/Scripts/jquery-1.6.1.min.js"></script>
<%--<SharePoint:ScriptLink ID="ScriptLink3" Name="~/_layouts/15/1033/TCSU/Scripts/jquery-1.6.1.min.js" runat="server" OnDemand="true" Localizable="false" />--%>
</asp:Content>
<asp:Content ID="Main" ContentPlaceHolderID="PlaceHolderMain" runat="server">
<script type="text/ecmascript" language="ecmascript">
    var lic;
    $(document).ready(function () {
        $('select[id*=field_value]').bind('change', function (e) {
            var discipline = $(this).val();
            $('input[id*=field_LocationVehicle]').val('');
            if (discipline != "") {
                $('input[id*=field_Discipline]').val(discipline);
                alert("method calling LoadLocationVehicles");
                SP.SOD.executeFunc('sp.js', 'SP.ClientContext', LoadLocationVehicles(discipline));
                //  ExecuteOrDelayUntilScriptLoaded(myCallback, "SP.js");
            } else {
                $("select[id*=lbLocationVehicles] > option").remove();
        $('select[id*=lbLocationVehicles]').bind('change', function (e) {
            var discipline = $(this).val();
            $('input[id*=field_LocationVehicle]').val(discipline);
    function LoadLocationVehicles(descipline) {
        alert("method called...");
        $("select[id*=lbLocationVehicles] > option").remove();
        var currctx =  SP.ClientContext.get_current();
        var targetList = currctx.get_web().get_lists().getByTitle('Disciplines');
        var query = "<View><Query><Where><Eq><FieldRef Name='Discipline'/><Value Type='Text'>" + descipline + "</Value></Eq></Where></Query></View>";
        var cq = new SP.CamlQuery();
        cq.set_viewXml(query);
        lic = targetList.getItems(cq);
        currctx.load(lic);
        currctx.executeQueryAsync(Function.createDelegate(this, getAllLocationsSuccess),
                        Function.createDelegate(this, getAllItemsFailure));
    function getAllDocumentsSuccess(sender, args) {
        var listEnumerator = lic.getEnumerator();
        while (listEnumerator.moveNext()) {
            $('input[id*=field_CDRLList]').val(listEnumerator.get_current().get_item("Title"));
    function getAllLocationsSuccess(sender, args) {
        var listEnumerator = lic.getEnumerator();
        while (listEnumerator.moveNext()) {
            var locationVehicle = listEnumerator.get_current().get_item("Title") + " - " + listEnumerator.get_current().get_item("Code")
            AddItem(locationVehicle, locationVehicle);
    function getAllItemsFailure(sender, args) {
        alert('Failed to get list items. \nError: ' + args.get_message() + '\nStackTrace: ' + args.get_stackTrace());
    function AddItem(text, val) {
        // Create an Option object
        $('select[id*=lbLocationVehicles]').append($('<option></option>').val(val).html(text));
</script>
</asp:Content>
Error message : Unable to get property 'get_current' of undefined or null reference
Amar
Master page JavaScript file  :
<SharePoint:ScriptLink language="javascript" name="core.js" OnDemand="true" runat="server" Localizable="false" />
 <SharePoint:ScriptLink language="javascript" name="menu.js" OnDemand="true" runat="server" Localizable="false" />
 <SharePoint:ScriptLink language="javascript" name="callout.js" OnDemand="true" runat="server" Localizable="false" />
 <SharePoint:ScriptLink language="javascript" name="sharing.js" OnDemand="true" runat="server" Localizable="false" />
 <SharePoint:ScriptLink language="javascript" name="suitelinks.js" OnDemand="true" runat="server" Localizable="false" />

Answer 1

I added following line script into my code then , it is working fine.  
<
asp:ContentID="PageHead"ContentPlaceHolderID="PlaceHolderAdditionalPageHead"runat="server">
<scripttype="text/javascript"src="/_layouts/15/sp.runtime.debug.js"></script>
<scripttype="text/javascript"src="/_layouts/15/sp.debug.js"></script>
<scripttype="text/javascript"src="/_layouts/15/sp.init.js"></script>
<scripttype="text/javascript"src="/_layouts/15/init.js"></script>
<scripttype="text/javascript"src="/_layouts/15/1033/ABC/Scripts/jquery-1.6.1.min.js"></script>
</
asp:Content>
Amar