Alternative to List.Include in EF - entity-framework

Question

I am having circular reference due to the EF code below. I have a Parent table with 2 childs and their grandchildren respectively. Is there any alternative to using Include, as I read something about Navigation property and it includes the parents in each of the child, causing the serialization having circular reference problem.
Error Message:
A circular reference was detected while serializing an object of type 'Product'.
This part is only to get retrieval and I don't need the parent reference back to each of the child. I debug inside and saw that inside each of the child, it has the parent reference back.
var query = db.Products.Include(c => c.ProductTriggers.Select(b => b.ProductTriggerItems))
.Include(d => d.ProductsExtra.Select(e => e.ProductAllotments.Select(m => m.ProductAllotmentDetails))).AsNoTracking();
return query.ToList();
Product Class
public partial class Product
{
public Product()
{
this.ProductExtras = new HashSet<ProductExtra>();
this.ProductTriggers = new HashSet<ProductTrigger>();
}
public int ProductID { get; set; }
public string ProductCode { get; set; }
public string ProductName { get; set; }
public virtual ICollection<ProductProduct> ProductExtras { get; set; }
public virtual ICollection<ProductTrigger> ProductTriggers { get; set; }
}
ProductExtra Class
public partial class ProductExtra
{
public ProductExtra()
{
this.ProductAllotments = new HashSet<ProductAllotment>();
}
public int ProductExtraID { get; set; }
public int ProductID { get; set; }
public virtual Product Product { get; set; }
public virtual ICollection<ProductAllotment> ProductAllotments { get; set; }
}
ProductAllotment Class
public partial class ProductAllotment
{
public ProductAllotment()
{
this.ProductAllotmentDetails = new HashSet<ProductAllotmentDetail>();
}
public int ProductAllotmentID { get; set; }
public int ProductExtraID { get; set; }
public virtual ProductExtra ProductExtra { get; set; }
public virtual ICollection<ProductAllotmentDetail> ProductAllotmentDetails { get; set; }
}
ProductTrigger Class
public partial class ProductTrigger
{
public ProductTrigger()
{
this.AddOnTriggerItems = new HashSet<ProductTriggerItem>();
}
public int ProductTriggerID { get; set; }
public int ProductID { get; set; }
public virtual Product Product { get; set; }
public virtual ICollection<ProductTriggerItem> ProductTriggerItems { get; set; }
}
ProductTriggerItem Class
public partial class ProductTriggerItem
{
public int ProductTriggerItemID { get; set; }
public int ProductTriggerID { get; set; }
public virtual ProductTrigger ProductTrigger { get; set; }
}